- R ({{MathWorld | urlname=R | title=R}}): R
- R- ({{MathWorld | urlname=R- | title=R-}}): R-
- Raabe's Test ({{MathWorld | urlname=RaabesTest | title=Raabe's Test}}): Raabe's Test
- Rabbit Constant ({{MathWorld | urlname=RabbitConstant | title=Rabbit Constant}}): Rabbit Constant
- Rabbit-Duck Illusion ({{MathWorld | urlname=Rabbit-DuckIllusion | title=Rabbit-Duck Illusion}}): Rabbit-Duck Illusion
- Rabbit Sequence ({{MathWorld | urlname=RabbitSequence | title=Rabbit Sequence}}): Rabbit Sequence
- Rabdology ({{MathWorld | urlname=Rabdology | title=Rabdology}}): Rabdology
- Rabin-Miller Strong Ps... ({{MathWorld | urlname=Rabin-MillerStrongPseudoprimeTest | title=Rabin-Miller Strong Ps...}}): Rabin-Miller Strong Ps...
- Rabinovich-Fabrikant E... ({{MathWorld | urlname=Rabinovich-FabrikantEquation | title=Rabinovich-Fabrikant E...}}): Rabinovich-Fabrikant E...
- Rabin's Compression Th... ({{MathWorld | urlname=RabinsCompressionTheorem | title=Rabin's Compression Th...}}): Rabin's Compression Th...
- Racah 6j-Symbol ({{MathWorld | urlname=Racah6j-Symbol | title=Racah 6j-Symbol}}): Racah 6j-Symbol
- Racah Coefficient ({{MathWorld | urlname=RacahCoefficient | title=Racah Coefficient}}): Racah Coefficient
- Racah Polynomial ({{MathWorld | urlname=RacahPolynomial | title=Racah Polynomial}}): Racah Polynomial
- Racah V-Coefficient ({{MathWorld | urlname=RacahV-Coefficient | title=Racah V-Coefficient}}): Racah V-Coefficient
- Racah W-Coefficient ({{MathWorld | urlname=RacahW-Coefficient | title=Racah W-Coefficient}}): Racah W-Coefficient
- Radau Quadrature ({{MathWorld | urlname=RadauQuadrature | title=Radau Quadrature}}): Radau Quadrature
- Rademacher Function ({{MathWorld | urlname=RademacherFunction | title=Rademacher Function}}): Rademacher Function
- Radial Curve ({{MathWorld | urlname=RadialCurve | title=Radial Curve}}): Radial Curve
- Radial Embedding ({{MathWorld | urlname=RadialEmbedding | title=Radial Embedding}}): Radial Embedding
- Radial Line ({{MathWorld | urlname=RadialLine | title=Radial Line}}): Radial Line
- Radial Point ({{MathWorld | urlname=RadialPoint | title=Radial Point}}): Radial Point
- Radian ({{MathWorld | urlname=Radian | title=Radian}}): Radian
- Radiant Point ({{MathWorld | urlname=RadiantPoint | title=Radiant Point}}): Radiant Point
- Radiation Symbol Theorem ({{MathWorld | urlname=RadiationSymbolTheorem | title=Radiation Symbol Theorem}}): Radiation Symbol Theorem
- Radical ({{MathWorld | urlname=Radical | title=Radical}}): Radical
- Radical Axis ({{MathWorld | urlname=RadicalAxis | title=Radical Axis}}): Radical Axis
- Radical Center ({{MathWorld | urlname=RadicalCenter | title=Radical Center}}): Radical Center
- Radical Circle ({{MathWorld | urlname=RadicalCircle | title=Radical Circle}}): Radical Circle
- Radical Denesting ({{MathWorld | urlname=RadicalDenesting | title=Radical Denesting}}): Radical Denesting
- Radical Integer ({{MathWorld | urlname=RadicalInteger | title=Radical Integer}}): Radical Integer
- Radical Line ({{MathWorld | urlname=RadicalLine | title=Radical Line}}): Radical Line
- Radical Root ({{MathWorld | urlname=RadicalRoot | title=Radical Root}}): Radical Root
- Radicand ({{MathWorld | urlname=Radicand | title=Radicand}}): Radicand
- Radius ({{MathWorld | urlname=Radius | title=Radius}}): Radius
- Radius of Convergence ({{MathWorld | urlname=RadiusofConvergence | title=Radius of Convergence}}): Radius of Convergence
- Radius of Curvature ({{MathWorld | urlname=RadiusofCurvature | title=Radius of Curvature}}): Radius of Curvature
- Radius of Gyration ({{MathWorld | urlname=RadiusofGyration | title=Radius of Gyration}}): Radius of Gyration
- Radius of Torsion ({{MathWorld | urlname=RadiusofTorsion | title=Radius of Torsion}}): Radius of Torsion
- Radius Vector ({{MathWorld | urlname=RadiusVector | title=Radius Vector}}): Radius Vector
- Radix ({{MathWorld | urlname=Radix | title=Radix}}): Radix
- Radix Sort ({{MathWorld | urlname=RadixSort | title=Radix Sort}}): Radix Sort
- Radon Measure ({{MathWorld | urlname=RadonMeasure | title=Radon Measure}}): Radon Measure
- Radon-Nikodym Derivative ({{MathWorld | urlname=Radon-NikodymDerivative | title=Radon-Nikodym Derivative}}): Radon-Nikodym Derivative
- Radon-Nikodym Theorem ({{MathWorld | urlname=Radon-NikodymTheorem | title=Radon-Nikodym Theorem}}): Radon-Nikodym Theorem
- Radon's Theorem ({{MathWorld | urlname=RadonsTheorem | title=Radon's Theorem}}): Radon's Theorem
- Radon Transform ({{MathWorld | urlname=RadonTransform | title=Radon Transform}}): Radon Transform
- Radon Transform--Cylinder ({{MathWorld | urlname=RadonTransformCylinder | title=Radon Transform--Cylinder}}): Radon Transform--Cylinder
- Radon Transform--Delta... ({{MathWorld | urlname=RadonTransformDeltaFunction | title=Radon Transform--Delta...}}): Radon Transform--Delta...
- Radon Transform--Gaussian ({{MathWorld | urlname=RadonTransformGaussian | title=Radon Transform--Gaussian}}): Radon Transform--Gaussian
- Radon Transform--Square ({{MathWorld | urlname=RadonTransformSquare | title=Radon Transform--Square}}): Radon Transform--Square
- Rado's Sigma Function ({{MathWorld | urlname=RadosSigmaFunction | title=Rado's Sigma Function}}): Rado's Sigma Function
- Railroad Track Problem ({{MathWorld | urlname=RailroadTrackProblem | title=Railroad Track Problem}}): Railroad Track Problem
- R-Algebra ({{MathWorld | urlname=R-Algebra | title=R-Algebra}}): R-Algebra
- Ramanujan 6-10-8 Identity ({{MathWorld | urlname=Ramanujan6-10-8Identity | title=Ramanujan 6-10-8 Identity}}): Ramanujan 6-10-8 Identity
- Ramanujan chi-Function ({{MathWorld | urlname=RamanujanChi-Function | title=Ramanujan chi-Function}}): Ramanujan chi-Function
- Ramanujan Constant ({{MathWorld | urlname=RamanujanConstant | title=Ramanujan Constant}}): Ramanujan Constant
- Ramanujan Continued Fr... ({{MathWorld | urlname=RamanujanContinuedFractions | title=Ramanujan Continued Fr...}}): Ramanujan Continued Fr...
- Ramanujan Cos/Cosh Ide... ({{MathWorld | urlname=RamanujanCosCoshIdentity | title=Ramanujan Cos/Cosh Ide...}}): Ramanujan Cos/Cosh Ide...
- Ramanujan-Eisenstein S... ({{MathWorld | urlname=Ramanujan-EisensteinSeries | title=Ramanujan-Eisenstein S...}}): Ramanujan-Eisenstein S...
- Ramanujan f-Function ({{MathWorld | urlname=Ramanujanf-Function | title=Ramanujan f-Function}}): Ramanujan f-Function
- Ramanujan g- and G-Fun... ({{MathWorld | urlname=Ramanujang-andG-Functions | title=Ramanujan g- and G-Fun...}}): Ramanujan g- and G-Fun...
- Ramanujan-Nagell Equation ({{MathWorld | urlname=Ramanujan-NagellEquation | title=Ramanujan-Nagell Equation}}): Ramanujan-Nagell Equation
- Ramanujan-Petersson Co... ({{MathWorld | urlname=Ramanujan-PeterssonConjecture | title=Ramanujan-Petersson Co...}}): Ramanujan-Petersson Co...
- Ramanujan phi-Function ({{MathWorld | urlname=RamanujanPhi-Function | title=Ramanujan phi-Function}}): Ramanujan phi-Function
- Ramanujan Prime ({{MathWorld | urlname=RamanujanPrime | title=Ramanujan Prime}}): Ramanujan Prime
- Ramanujan Prize ({{MathWorld | urlname=RamanujanPrize | title=Ramanujan Prize}}): Ramanujan Prize
- Ramanujan psi-Function ({{MathWorld | urlname=RamanujanPsi-Function | title=Ramanujan psi-Function}}): Ramanujan psi-Function
- Ramanujan Psi Sum ({{MathWorld | urlname=RamanujanPsiSum | title=Ramanujan Psi Sum}}): Ramanujan Psi Sum
- Ramanujan's AGM Contin... ({{MathWorld | urlname=RamanujansAGMContinuedFraction | title=Ramanujan's AGM Contin...}}): Ramanujan's AGM Contin...
- Ramanujan's Formula ({{MathWorld | urlname=RamanujansFormula | title=Ramanujan's Formula}}): Ramanujan's Formula
- Ramanujan's Hypergeome... ({{MathWorld | urlname=RamanujansHypergeometricIdentity | title=Ramanujan's Hypergeome...}}): Ramanujan's Hypergeome...
- Ramanujan's Hypothesis ({{MathWorld | urlname=RamanujansHypothesis | title=Ramanujan's Hypothesis}}): Ramanujan's Hypothesis
- Ramanujan's Identity ({{MathWorld | urlname=RamanujansIdentity | title=Ramanujan's Identity}}): Ramanujan's Identity
- Ramanujan's Integral ({{MathWorld | urlname=RamanujansIntegral | title=Ramanujan's Integral}}): Ramanujan's Integral
- Ramanujan's Interpolat... ({{MathWorld | urlname=RamanujansInterpolationFormula | title=Ramanujan's Interpolat...}}): Ramanujan's Interpolat...
- Ramanujan's Master The... ({{MathWorld | urlname=RamanujansMasterTheorem | title=Ramanujan's Master The...}}): Ramanujan's Master The...
- Ramanujan-Soldner Cons... ({{MathWorld | urlname=Ramanujan-SoldnerConstant | title=Ramanujan-Soldner Cons...}}): Ramanujan-Soldner Cons...
- Ramanujan's Square Equ... ({{MathWorld | urlname=RamanujansSquareEquation | title=Ramanujan's Square Equ...}}): Ramanujan's Square Equ...
- Ramanujan's Sum ({{MathWorld | urlname=RamanujansSum | title=Ramanujan's Sum}}): Ramanujan's Sum
- Ramanujan's Sum Identity ({{MathWorld | urlname=RamanujansSumIdentity | title=Ramanujan's Sum Identity}}): Ramanujan's Sum Identity
- Ramanujan's Tau Dirich... ({{MathWorld | urlname=RamanujansTauDirichletSeries | title=Ramanujan's Tau Dirich...}}): Ramanujan's Tau Dirich...
- Ramanujan's Tau Function ({{MathWorld | urlname=RamanujansTauFunction | title=Ramanujan's Tau Function}}): Ramanujan's Tau Function
- RamanujanTau ({{MathWorld | urlname=RamanujanTau | title=RamanujanTau}}): RamanujanTau
- RamanujanTauL ({{MathWorld | urlname=RamanujanTauL | title=RamanujanTauL}}): RamanujanTauL
- RamanujanTauTheta ({{MathWorld | urlname=RamanujanTauTheta | title=RamanujanTauTheta}}): RamanujanTauTheta
- RamanujanTauZ ({{MathWorld | urlname=RamanujanTauZ | title=RamanujanTauZ}}): RamanujanTauZ
- Ramanujan Theta Functions ({{MathWorld | urlname=RamanujanThetaFunctions | title=Ramanujan Theta Functions}}): Ramanujan Theta Functions
- Ramification Group ({{MathWorld | urlname=RamificationGroup | title=Ramification Group}}): Ramification Group
- Ramification Index ({{MathWorld | urlname=RamificationIndex | title=Ramification Index}}): Ramification Index
- Ramp Function ({{MathWorld | urlname=RampFunction | title=Ramp Function}}): Ramp Function
- Ramphoid Cusp ({{MathWorld | urlname=RamphoidCusp | title=Ramphoid Cusp}}): Ramphoid Cusp
- Ramsey Number ({{MathWorld | urlname=RamseyNumber | title=Ramsey Number}}): Ramsey Number
- Ramsey's Theorem ({{MathWorld | urlname=RamseysTheorem | title=Ramsey's Theorem}}): Ramsey's Theorem
- Ramsey Theory ({{MathWorld | urlname=RamseyTheory | title=Ramsey Theory}}): Ramsey Theory
- Ramus Tree ({{MathWorld | urlname=RamusTree | title=Ramus Tree}}): Ramus Tree
- Randelbrot Set ({{MathWorld | urlname=RandelbrotSet | title=Randelbrot Set}}): Randelbrot Set
- Random ({{MathWorld | urlname=Random | title=Random}}): Random
- Random Close Packing ({{MathWorld | urlname=RandomClosePacking | title=Random Close Packing}}): Random Close Packing
- Random Composition ({{MathWorld | urlname=RandomComposition | title=Random Composition}}): Random Composition
- Random Distribution ({{MathWorld | urlname=RandomDistribution | title=Random Distribution}}): Random Distribution
- Random Dot Stereogram ({{MathWorld | urlname=RandomDotStereogram | title=Random Dot Stereogram}}): Random Dot Stereogram
- Random Ellipsoid Packing ({{MathWorld | urlname=RandomEllipsoidPacking | title=Random Ellipsoid Packing}}): Random Ellipsoid Packing
- Random Fibonacci Sequence ({{MathWorld | urlname=RandomFibonacciSequence | title=Random Fibonacci Sequence}}): Random Fibonacci Sequence
- Random Graph ({{MathWorld | urlname=RandomGraph | title=Random Graph}}): Random Graph
- Random Matrix ({{MathWorld | urlname=RandomMatrix | title=Random Matrix}}): Random Matrix
- Random Normal Deviate ({{MathWorld | urlname=RandomNormalDeviate | title=Random Normal Deviate}}): Random Normal Deviate
- Random Number ({{MathWorld | urlname=RandomNumber | title=Random Number}}): Random Number
- Random Partition ({{MathWorld | urlname=RandomPartition | title=Random Partition}}): Random Partition
- Random Percolation ({{MathWorld | urlname=RandomPercolation | title=Random Percolation}}): Random Percolation
- Random Permutation ({{MathWorld | urlname=RandomPermutation | title=Random Permutation}}): Random Permutation
- Random Polygon ({{MathWorld | urlname=RandomPolygon | title=Random Polygon}}): Random Polygon
- Random Polynomial ({{MathWorld | urlname=RandomPolynomial | title=Random Polynomial}}): Random Polynomial
- Random Prime ({{MathWorld | urlname=RandomPrime | title=Random Prime}}): Random Prime
- RandomSample ({{MathWorld | urlname=RandomSample | title=RandomSample}}): RandomSample
- Random Sphere Packing ({{MathWorld | urlname=RandomSpherePacking | title=Random Sphere Packing}}): Random Sphere Packing
- Random Tableau ({{MathWorld | urlname=RandomTableau | title=Random Tableau}}): Random Tableau
- Random Variable ({{MathWorld | urlname=RandomVariable | title=Random Variable}}): Random Variable
- Random Variate ({{MathWorld | urlname=RandomVariate | title=Random Variate}}): Random Variate
- Random Walk ({{MathWorld | urlname=RandomWalk | title=Random Walk}}): Random Walk
- Random Walk--1-Dimensi... ({{MathWorld | urlname=RandomWalk1-Dimensional | title=Random Walk--1-Dimensi...}}): Random Walk--1-Dimensi...
- Random Walk--2-Dimensi... ({{MathWorld | urlname=RandomWalk2-Dimensional | title=Random Walk--2-Dimensi...}}): Random Walk--2-Dimensi...
- Random Walk--3-Dimensi... ({{MathWorld | urlname=RandomWalk3-Dimensional | title=Random Walk--3-Dimensi...}}): Random Walk--3-Dimensi...
- Random Young Tableau ({{MathWorld | urlname=RandomYoungTableau | title=Random Young Tableau}}): Random Young Tableau
- Range ({{MathWorld | urlname=Range | title=Range}}): Range
- Rank ({{MathWorld | urlname=Rank | title=Rank}}): Rank
- Rank Matrix ({{MathWorld | urlname=RankMatrix | title=Rank Matrix}}): Rank Matrix
- Rank-Nullity Theorem ({{MathWorld | urlname=Rank-NullityTheorem | title=Rank-Nullity Theorem}}): Rank-Nullity Theorem
- Rank Order Correlation... ({{MathWorld | urlname=RankOrderCorrelationCoefficient | title=Rank Order Correlation...}}): Rank Order Correlation...
- Rank Polynomial ({{MathWorld | urlname=RankPolynomial | title=Rank Polynomial}}): Rank Polynomial
- Rank Test ({{MathWorld | urlname=RankTest | title=Rank Test}}): Rank Test
- Ranunculoid ({{MathWorld | urlname=Ranunculoid | title=Ranunculoid}}): Ranunculoid
- Rapid Rumor Ramification ({{MathWorld | urlname=RapidRumorRamification | title=Rapid Rumor Ramification}}): Rapid Rumor Ramification
- RAT-Free Set ({{MathWorld | urlname=RAT-FreeSet | title=RAT-Free Set}}): RAT-Free Set
- Ratio ({{MathWorld | urlname=Ratio | title=Ratio}}): Ratio
- Ratio Distribution ({{MathWorld | urlname=RatioDistribution | title=Ratio Distribution}}): Ratio Distribution
- Rational Amicable Pair ({{MathWorld | urlname=RationalAmicablePair | title=Rational Amicable Pair}}): Rational Amicable Pair
- Rational Approximation ({{MathWorld | urlname=RationalApproximation | title=Rational Approximation}}): Rational Approximation
- Rational Canonical Form ({{MathWorld | urlname=RationalCanonicalForm | title=Rational Canonical Form}}): Rational Canonical Form
- Rational Cuboid ({{MathWorld | urlname=RationalCuboid | title=Rational Cuboid}}): Rational Cuboid
- Rational Diagonal ({{MathWorld | urlname=RationalDiagonal | title=Rational Diagonal}}): Rational Diagonal
- Rational Distance Problem ({{MathWorld | urlname=RationalDistanceProblem | title=Rational Distance Problem}}): Rational Distance Problem
- Rational Distances ({{MathWorld | urlname=RationalDistances | title=Rational Distances}}): Rational Distances
- Rational Domain ({{MathWorld | urlname=RationalDomain | title=Rational Domain}}): Rational Domain
- Rational Double Point ({{MathWorld | urlname=RationalDoublePoint | title=Rational Double Point}}): Rational Double Point
- Rational Function ({{MathWorld | urlname=RationalFunction | title=Rational Function}}): Rational Function
- Rational Integer ({{MathWorld | urlname=RationalInteger | title=Rational Integer}}): Rational Integer
- Rational Number ({{MathWorld | urlname=RationalNumber | title=Rational Number}}): Rational Number
- Rational Point ({{MathWorld | urlname=RationalPoint | title=Rational Point}}): Rational Point
- Rational Polynomial ({{MathWorld | urlname=RationalPolynomial | title=Rational Polynomial}}): Rational Polynomial
- Rational Polynomial Fu... ({{MathWorld | urlname=RationalPolynomialFunction | title=Rational Polynomial Fu...}}): Rational Polynomial Fu...
- Rational Quadrilateral ({{MathWorld | urlname=RationalQuadrilateral | title=Rational Quadrilateral}}): Rational Quadrilateral
- Rationals ({{MathWorld | urlname=Rationals | title=Rationals}}): Rationals
- Rational Spiral ({{MathWorld | urlname=RationalSpiral | title=Rational Spiral}}): Rational Spiral
- Rational Triangle ({{MathWorld | urlname=RationalTriangle | title=Rational Triangle}}): Rational Triangle
- Rational Zero Theorem ({{MathWorld | urlname=RationalZeroTheorem | title=Rational Zero Theorem}}): Rational Zero Theorem
- Ratio of Magnification ({{MathWorld | urlname=RatioofMagnification | title=Ratio of Magnification}}): Ratio of Magnification
- Ratio Test ({{MathWorld | urlname=RatioTest | title=Ratio Test}}): Ratio Test
- RATS Sequence ({{MathWorld | urlname=RATSSequence | title=RATS Sequence}}): RATS Sequence
- Raw Moment ({{MathWorld | urlname=RawMoment | title=Raw Moment}}): Raw Moment
- Ray ({{MathWorld | urlname=Ray | title=Ray}}): Ray
- Rayleigh Differential... ({{MathWorld | urlname=RayleighDifferentialEquation | title=Rayleigh Differential...}}): Rayleigh Differential...
- Rayleigh Distribution ({{MathWorld | urlname=RayleighDistribution | title=Rayleigh Distribution}}): Rayleigh Distribution
- Rayleigh Function ({{MathWorld | urlname=RayleighFunction | title=Rayleigh Function}}): Rayleigh Function
- Rayleigh-Ritz Variatio... ({{MathWorld | urlname=Rayleigh-RitzVariationalTechnique | title=Rayleigh-Ritz Variatio...}}): Rayleigh-Ritz Variatio...
- Rayleigh's Formulas ({{MathWorld | urlname=RayleighsFormulas | title=Rayleigh's Formulas}}): Rayleigh's Formulas
- Rayleigh's Theorem ({{MathWorld | urlname=RayleighsTheorem | title=Rayleigh's Theorem}}): Rayleigh's Theorem
- Rayleigh Wave Equation ({{MathWorld | urlname=RayleighWaveEquation | title=Rayleigh Wave Equation}}): Rayleigh Wave Equation
- R_ ({{MathWorld | urlname=R-Bar | title=R_}}): R_
- Re ({{MathWorld | urlname=Re | title=Re}}): Re
- Reachable ({{MathWorld | urlname=Reachable | title=Reachable}}): Reachable
- Reaching Algorithm ({{MathWorld | urlname=ReachingAlgorithm | title=Reaching Algorithm}}): Reaching Algorithm
- Real Analysis ({{MathWorld | urlname=RealAnalysis | title=Real Analysis}}): Real Analysis
- Real Analytic Function ({{MathWorld | urlname=RealAnalyticFunction | title=Real Analytic Function}}): Real Analytic Function
- Real Axis ({{MathWorld | urlname=RealAxis | title=Real Axis}}): Real Axis
- Real Function ({{MathWorld | urlname=RealFunction | title=Real Function}}): Real Function
- Realizer ({{MathWorld | urlname=Realizer | title=Realizer}}): Realizer
- Real Line ({{MathWorld | urlname=RealLine | title=Real Line}}): Real Line
- Real Manifold ({{MathWorld | urlname=RealManifold | title=Real Manifold}}): Real Manifold
- Real Matrix ({{MathWorld | urlname=RealMatrix | title=Real Matrix}}): Real Matrix
- Real Measure ({{MathWorld | urlname=RealMeasure | title=Real Measure}}): Real Measure
- Real Normed Algebra ({{MathWorld | urlname=RealNormedAlgebra | title=Real Normed Algebra}}): Real Normed Algebra
- Real Number ({{MathWorld | urlname=RealNumber | title=Real Number}}): Real Number
- Real Number Picking ({{MathWorld | urlname=RealNumberPicking | title=Real Number Picking}}): Real Number Picking
- Real Numbers ({{MathWorld | urlname=RealNumbers | title=Real Numbers}}): Real Numbers
- Real Part ({{MathWorld | urlname=RealPart | title=Real Part}}): Real Part
- Real Polynomial ({{MathWorld | urlname=RealPolynomial | title=Real Polynomial}}): Real Polynomial
- Real Projective Plane ({{MathWorld | urlname=RealProjectivePlane | title=Real Projective Plane}}): Real Projective Plane
- Real Projective Space ({{MathWorld | urlname=RealProjectiveSpace | title=Real Projective Space}}): Real Projective Space
- RealQ ({{MathWorld | urlname=RealQ | title=RealQ}}): RealQ
- Real Quadratic Field ({{MathWorld | urlname=RealQuadraticField | title=Real Quadratic Field}}): Real Quadratic Field
- Reals ({{MathWorld | urlname=Reals | title=Reals}}): Reals
- Real Space ({{MathWorld | urlname=RealSpace | title=Real Space}}): Real Space
- Real-Valued Function ({{MathWorld | urlname=Real-ValuedFunction | title=Real-Valued Function}}): Real-Valued Function
- Real Variable ({{MathWorld | urlname=RealVariable | title=Real Variable}}): Real Variable
- Real Vector ({{MathWorld | urlname=RealVector | title=Real Vector}}): Real Vector
- Real Vector Bundle ({{MathWorld | urlname=RealVectorBundle | title=Real Vector Bundle}}): Real Vector Bundle
- Real Vector Space ({{MathWorld | urlname=RealVectorSpace | title=Real Vector Space}}): Real Vector Space
- Rearrangement Prime Pair ({{MathWorld | urlname=RearrangementPrimePair | title=Rearrangement Prime Pair}}): Rearrangement Prime Pair
- Rearrangement Theorem ({{MathWorld | urlname=RearrangementTheorem | title=Rearrangement Theorem}}): Rearrangement Theorem
- Recamán's Sequence ({{MathWorld | urlname=RecamansSequence | title=Recamán's Sequence}}): Recamán's Sequence
- Reciprocal ({{MathWorld | urlname=Reciprocal | title=Reciprocal}}): Reciprocal
- Reciprocal Conjugation ({{MathWorld | urlname=ReciprocalConjugation | title=Reciprocal Conjugation}}): Reciprocal Conjugation
- Reciprocal Curve ({{MathWorld | urlname=ReciprocalCurve | title=Reciprocal Curve}}): Reciprocal Curve
- Reciprocal Difference ({{MathWorld | urlname=ReciprocalDifference | title=Reciprocal Difference}}): Reciprocal Difference
- Reciprocal Fibonacci C... ({{MathWorld | urlname=ReciprocalFibonacciConstant | title=Reciprocal Fibonacci C...}}): Reciprocal Fibonacci C...
- Reciprocal Lucas Constant ({{MathWorld | urlname=ReciprocalLucasConstant | title=Reciprocal Lucas Constant}}): Reciprocal Lucas Constant
- Reciprocal Matrix ({{MathWorld | urlname=ReciprocalMatrix | title=Reciprocal Matrix}}): Reciprocal Matrix
- Reciprocal Multifactor... ({{MathWorld | urlname=ReciprocalMultifactorialConstant | title=Reciprocal Multifactor...}}): Reciprocal Multifactor...
- Reciprocal Permutation ({{MathWorld | urlname=ReciprocalPermutation | title=Reciprocal Permutation}}): Reciprocal Permutation
- Reciprocal Polyhedron ({{MathWorld | urlname=ReciprocalPolyhedron | title=Reciprocal Polyhedron}}): Reciprocal Polyhedron
- Reciprocal Polynomial ({{MathWorld | urlname=ReciprocalPolynomial | title=Reciprocal Polynomial}}): Reciprocal Polynomial
- Reciprocal Prime Constant ({{MathWorld | urlname=ReciprocalPrimeConstant | title=Reciprocal Prime Constant}}): Reciprocal Prime Constant
- Reciprocating Sphere ({{MathWorld | urlname=ReciprocatingSphere | title=Reciprocating Sphere}}): Reciprocating Sphere
- Reciprocation ({{MathWorld | urlname=Reciprocation | title=Reciprocation}}): Reciprocation
- Reciprocity Law ({{MathWorld | urlname=ReciprocityLaw | title=Reciprocity Law}}): Reciprocity Law
- Reciprocity Theorem ({{MathWorld | urlname=ReciprocityTheorem | title=Reciprocity Theorem}}): Reciprocity Theorem
- Recognize ({{MathWorld | urlname=Recognize | title=Recognize}}): Recognize
- Recontres Problem ({{MathWorld | urlname=RecontresProblem | title=Recontres Problem}}): Recontres Problem
- Record Setting ({{MathWorld | urlname=RecordSetting | title=Record Setting}}): Record Setting
- Rectangle ({{MathWorld | urlname=Rectangle | title=Rectangle}}): Rectangle
- Rectangle Function ({{MathWorld | urlname=RectangleFunction | title=Rectangle Function}}): Rectangle Function
- Rectangle Squaring ({{MathWorld | urlname=RectangleSquaring | title=Rectangle Squaring}}): Rectangle Squaring
- Rectangle Tiling ({{MathWorld | urlname=RectangleTiling | title=Rectangle Tiling}}): Rectangle Tiling
- Rectangular Coordinates ({{MathWorld | urlname=RectangularCoordinates | title=Rectangular Coordinates}}): Rectangular Coordinates
- Rectangular Distribution ({{MathWorld | urlname=RectangularDistribution | title=Rectangular Distribution}}): Rectangular Distribution
- Rectangular Hyperbola ({{MathWorld | urlname=RectangularHyperbola | title=Rectangular Hyperbola}}): Rectangular Hyperbola
- Rectangular Matrix ({{MathWorld | urlname=RectangularMatrix | title=Rectangular Matrix}}): Rectangular Matrix
- Rectangular Parallelep... ({{MathWorld | urlname=RectangularParallelepiped | title=Rectangular Parallelep...}}): Rectangular Parallelep...
- Rectangular Projection ({{MathWorld | urlname=RectangularProjection | title=Rectangular Projection}}): Rectangular Projection
- Rectifiable Current ({{MathWorld | urlname=RectifiableCurrent | title=Rectifiable Current}}): Rectifiable Current
- Rectifiable Set ({{MathWorld | urlname=RectifiableSet | title=Rectifiable Set}}): Rectifiable Set
- Rectification ({{MathWorld | urlname=Rectification | title=Rectification}}): Rectification
- Rectifying Latitude ({{MathWorld | urlname=RectifyingLatitude | title=Rectifying Latitude}}): Rectifying Latitude
- Rectifying Plane ({{MathWorld | urlname=RectifyingPlane | title=Rectifying Plane}}): Rectifying Plane
- Rectilinear Crossing N... ({{MathWorld | urlname=RectilinearCrossingNumber | title=Rectilinear Crossing N...}}): Rectilinear Crossing N...
- Rectilinear Projection ({{MathWorld | urlname=RectilinearProjection | title=Rectilinear Projection}}): Rectilinear Projection
- Recurrence Equation ({{MathWorld | urlname=RecurrenceEquation | title=Recurrence Equation}}): Recurrence Equation
- Recurrence Plot ({{MathWorld | urlname=RecurrencePlot | title=Recurrence Plot}}): Recurrence Plot
- Recurrence Relation ({{MathWorld | urlname=RecurrenceRelation | title=Recurrence Relation}}): Recurrence Relation
- Recurrence Relation Si... ({{MathWorld | urlname=RecurrenceRelationSignature | title=Recurrence Relation Si...}}): Recurrence Relation Si...
- Recurrence Sequence ({{MathWorld | urlname=RecurrenceSequence | title=Recurrence Sequence}}): Recurrence Sequence
- RecurrenceTable ({{MathWorld | urlname=RecurrenceTable | title=RecurrenceTable}}): RecurrenceTable
- Recurring Decimal ({{MathWorld | urlname=RecurringDecimal | title=Recurring Decimal}}): Recurring Decimal
- Recurring Digital Inva... ({{MathWorld | urlname=RecurringDigitalInvariant | title=Recurring Digital Inva...}}): Recurring Digital Inva...
- Recursion ({{MathWorld | urlname=Recursion | title=Recursion}}): Recursion
- Recursion Theorem ({{MathWorld | urlname=RecursionTheorem | title=Recursion Theorem}}): Recursion Theorem
- Recursive Function ({{MathWorld | urlname=RecursiveFunction | title=Recursive Function}}): Recursive Function
- Recursively Enumerable... ({{MathWorld | urlname=RecursivelyEnumerableSet | title=Recursively Enumerable...}}): Recursively Enumerable...
- Recursively Isomorphic ({{MathWorld | urlname=RecursivelyIsomorphic | title=Recursively Isomorphic}}): Recursively Isomorphic
- Recursively Undecidable ({{MathWorld | urlname=RecursivelyUndecidable | title=Recursively Undecidable}}): Recursively Undecidable
- Recursive Monotone Sta... ({{MathWorld | urlname=RecursiveMonotoneStableQuadrature | title=Recursive Monotone Sta...}}): Recursive Monotone Sta...
- Recursive Sequence ({{MathWorld | urlname=RecursiveSequence | title=Recursive Sequence}}): Recursive Sequence
- Recursive Set ({{MathWorld | urlname=RecursiveSet | title=Recursive Set}}): Recursive Set
- Red-Black Tree ({{MathWorld | urlname=Red-BlackTree | title=Red-Black Tree}}): Red-Black Tree
- Redheffer Matrix ({{MathWorld | urlname=RedhefferMatrix | title=Redheffer Matrix}}): Redheffer Matrix
- Red Net ({{MathWorld | urlname=RedNet | title=Red Net}}): Red Net
- Reduce ({{MathWorld | urlname=Reduce | title=Reduce}}): Reduce
- Reduced Amicable Pair ({{MathWorld | urlname=ReducedAmicablePair | title=Reduced Amicable Pair}}): Reduced Amicable Pair
- Reduced Binary Quadrat... ({{MathWorld | urlname=ReducedBinaryQuadraticForm | title=Reduced Binary Quadrat...}}): Reduced Binary Quadrat...
- Reduced Echelon Form ({{MathWorld | urlname=ReducedEchelonForm | title=Reduced Echelon Form}}): Reduced Echelon Form
- Reduced Fraction ({{MathWorld | urlname=ReducedFraction | title=Reduced Fraction}}): Reduced fraction
- Reduced Knot Diagram ({{MathWorld | urlname=ReducedKnotDiagram | title=Reduced Knot Diagram}}): Reduced Knot Diagram
- Reduced Latitude ({{MathWorld | urlname=ReducedLatitude | title=Reduced Latitude}}): Reduced Latitude
- Reduced Maxwell-Bloch... ({{MathWorld | urlname=ReducedMaxwell-BlochEquations | title=Reduced Maxwell-Bloch...}}): Reduced Maxwell-Bloch...
- Reduced Residue System ({{MathWorld | urlname=ReducedResidueSystem | title=Reduced Residue System}}): Reduced Residue System
- Reduced Root System ({{MathWorld | urlname=ReducedRootSystem | title=Reduced Root System}}): Reduced Root System
- Reducible ({{MathWorld | urlname=Reducible | title=Reducible}}): Reducible
- Reducible Crossing ({{MathWorld | urlname=ReducibleCrossing | title=Reducible Crossing}}): Reducible Crossing
- Reducible Fraction ({{MathWorld | urlname=ReducibleFraction | title=Reducible Fraction}}): Reducible Fraction
- Reducible Matrix ({{MathWorld | urlname=ReducibleMatrix | title=Reducible Matrix}}): Reducible Matrix
- Reducible Representation ({{MathWorld | urlname=ReducibleRepresentation | title=Reducible Representation}}): Reducible Representation
- Reductio ad Absurdum ({{MathWorld | urlname=ReductioadAbsurdum | title=Reductio ad Absurdum}}): Reductio ad Absurdum
- Reduction Algorithm ({{MathWorld | urlname=ReductionAlgorithm | title=Reduction Algorithm}}): Reduction Algorithm
- Reduction of Order ({{MathWorld | urlname=ReductionofOrder | title=Reduction of Order}}): Reduction of Order
- Reduction Order ({{MathWorld | urlname=ReductionOrder | title=Reduction Order}}): Reduction Order
- Reduction System ({{MathWorld | urlname=ReductionSystem | title=Reduction System}}): Reduction System
- Reduction Theorem ({{MathWorld | urlname=ReductionTheorem | title=Reduction Theorem}}): Reduction Theorem
- Redundancy ({{MathWorld | urlname=Redundancy | title=Redundancy}}): Redundancy
- Reeb Foliation ({{MathWorld | urlname=ReebFoliation | title=Reeb Foliation}}): Reeb Foliation
- Reed-Muller Error-Corr... ({{MathWorld | urlname=Reed-MullerError-CorrectingCode | title=Reed-Muller Error-Corr...}}): Reed-Muller Error-Corr...
- Reed-Sloane Algorithm ({{MathWorld | urlname=Reed-SloaneAlgorithm | title=Reed-Sloane Algorithm}}): Reed-Sloane Algorithm
- Reef Knot ({{MathWorld | urlname=ReefKnot | title=Reef Knot}}): Reef Knot
- Ree Group ({{MathWorld | urlname=ReeGroup | title=Ree Group}}): Ree Group
- Re-Entrant Circuit ({{MathWorld | urlname=Re-EntrantCircuit | title=Re-Entrant Circuit}}): Re-Entrant Circuit
- Rees Module ({{MathWorld | urlname=ReesModule | title=Rees Module}}): Rees Module
- Rees Ring ({{MathWorld | urlname=ReesRing | title=Rees Ring}}): Rees Ring
- Refactorable Number ({{MathWorld | urlname=RefactorableNumber | title=Refactorable Number}}): Refactorable Number
- Reference Polynomial ({{MathWorld | urlname=ReferencePolynomial | title=Reference Polynomial}}): Reference Polynomial
- Reference Triangle ({{MathWorld | urlname=ReferenceTriangle | title=Reference Triangle}}): Reference Triangle
- Refined Alternating Si... ({{MathWorld | urlname=RefinedAlternatingSignMatrixConjecture | title=Refined Alternating Si...}}): Refined Alternating Si...
- Refinement ({{MathWorld | urlname=Refinement | title=Refinement}}): Refinement
- Reflection ({{MathWorld | urlname=Reflection | title=Reflection}}): Reflection
- Reflection Circle ({{MathWorld | urlname=ReflectionCircle | title=Reflection Circle}}): Reflection Circle
- Reflection Formula ({{MathWorld | urlname=ReflectionFormula | title=Reflection Formula}}): Reflection Formula
- Reflection Property ({{MathWorld | urlname=ReflectionProperty | title=Reflection Property}}): Reflection Property
- Reflection Relation ({{MathWorld | urlname=ReflectionRelation | title=Reflection Relation}}): Reflection Relation
- Reflection Triangle ({{MathWorld | urlname=ReflectionTriangle | title=Reflection Triangle}}): Reflection Triangle
- Reflex Angle ({{MathWorld | urlname=ReflexAngle | title=Reflex Angle}}): Reflex Angle
- Reflexible ({{MathWorld | urlname=Reflexible | title=Reflexible}}): Reflexible
- Reflexible Map ({{MathWorld | urlname=ReflexibleMap | title=Reflexible Map}}): Reflexible Map
- Reflexive ({{MathWorld | urlname=Reflexive | title=Reflexive}}): Reflexive
- Reflexive Banach Space ({{MathWorld | urlname=ReflexiveBanachSpace | title=Reflexive Banach Space}}): Reflexive Banach Space
- Reflexive Closure ({{MathWorld | urlname=ReflexiveClosure | title=Reflexive Closure}}): Reflexive Closure
- Reflexive Graph ({{MathWorld | urlname=ReflexiveGraph | title=Reflexive Graph}}): Reflexive Graph
- Reflexive Polyhedron ({{MathWorld | urlname=ReflexivePolyhedron | title=Reflexive Polyhedron}}): Reflexive Polyhedron
- Reflexive Reduction ({{MathWorld | urlname=ReflexiveReduction | title=Reflexive Reduction}}): Reflexive Reduction
- Reflexivity ({{MathWorld | urlname=Reflexivity | title=Reflexivity}}): Reflexivity
- Region ({{MathWorld | urlname=Region | title=Region}}): Region
- Register Machine ({{MathWorld | urlname=RegisterMachine | title=Register Machine}}): Register Machine
- Regression ({{MathWorld | urlname=Regression | title=Regression}}): Regression
- Regression Coefficient ({{MathWorld | urlname=RegressionCoefficient | title=Regression Coefficient}}): Regression Coefficient
- Regression to the Mean ({{MathWorld | urlname=RegressiontotheMean | title=Regression to the Mean}}): Regression to the Mean
- Regula Falsi ({{MathWorld | urlname=RegulaFalsi | title=Regula Falsi}}): Regula Falsi
- Regular Borel Measure ({{MathWorld | urlname=RegularBorelMeasure | title=Regular Borel Measure}}): Regular Borel Measure
- Regular Decagon ({{MathWorld | urlname=RegularDecagon | title=Regular Decagon}}): Regular Decagon
- Regular Dodecagon ({{MathWorld | urlname=RegularDodecagon | title=Regular Dodecagon}}): Regular Dodecagon
- Regular Expression ({{MathWorld | urlname=RegularExpression | title=Regular Expression}}): Regular Expression
- Regular Function ({{MathWorld | urlname=RegularFunction | title=Regular Function}}): Regular Function
- Regular Graph ({{MathWorld | urlname=RegularGraph | title=Regular Graph}}): Regular Graph
- Regular Hendecagon ({{MathWorld | urlname=RegularHendecagon | title=Regular Hendecagon}}): Regular Hendecagon
- Regular Heptagon ({{MathWorld | urlname=RegularHeptagon | title=Regular Heptagon}}): Regular Heptagon
- Regular Hexagon ({{MathWorld | urlname=RegularHexagon | title=Regular Hexagon}}): Regular Hexagon
- Regular Homotopy ({{MathWorld | urlname=RegularHomotopy | title=Regular Homotopy}}): Regular Homotopy
- Regular Isotopy ({{MathWorld | urlname=RegularIsotopy | title=Regular Isotopy}}): Regular Isotopy
- Regular Isotopy Invariant ({{MathWorld | urlname=RegularIsotopyInvariant | title=Regular Isotopy Invariant}}): Regular Isotopy Invariant
- Regularity Axiom ({{MathWorld | urlname=RegularityAxiom | title=Regularity Axiom}}): Regularity Axiom
- Regularity Lemma ({{MathWorld | urlname=RegularityLemma | title=Regularity Lemma}}): Regularity Lemma
- Regularity Theorem ({{MathWorld | urlname=RegularityTheorem | title=Regularity Theorem}}): Regularity Theorem
- Regularization ({{MathWorld | urlname=Regularization | title=Regularization}}): Regularization
- Regularized Beta Function ({{MathWorld | urlname=RegularizedBetaFunction | title=Regularized Beta Function}}): Regularized Beta Function
- Regularized Gamma Func... ({{MathWorld | urlname=RegularizedGammaFunction | title=Regularized Gamma Func...}}): Regularized Gamma Func...
- Regularized Hypergeome... ({{MathWorld | urlname=RegularizedHypergeometricFunction | title=Regularized Hypergeome...}}): Regularized Hypergeome...
- Regularized Long-Wave... ({{MathWorld | urlname=RegularizedLong-WaveEquation | title=Regularized Long-Wave...}}): Regularized Long-Wave...
- Regularized Product ({{MathWorld | urlname=RegularizedProduct | title=Regularized Product}}): Regularized Product
- Regularized Sum ({{MathWorld | urlname=RegularizedSum | title=Regularized Sum}}): Regularized Sum
- Regular Local Ring ({{MathWorld | urlname=RegularLocalRing | title=Regular Local Ring}}): Regular Local Ring
- Regular Matrix ({{MathWorld | urlname=RegularMatrix | title=Regular Matrix}}): Regular Matrix
- Regular Nonagon ({{MathWorld | urlname=RegularNonagon | title=Regular Nonagon}}): Regular Nonagon
- Regular Number ({{MathWorld | urlname=RegularNumber | title=Regular Number}}): Regular Number
- Regular Octagon ({{MathWorld | urlname=RegularOctagon | title=Regular Octagon}}): Regular Octagon
- Regular Paperfolding S... ({{MathWorld | urlname=RegularPaperfoldingSequence | title=Regular Paperfolding S...}}): Regular Paperfolding S...
- Regular Parameterization ({{MathWorld | urlname=RegularParameterization | title=Regular Parameterization}}): Regular Parameterization
- Regular Partial Differ... ({{MathWorld | urlname=RegularPartialDifferentialEquation | title=Regular Partial Differ...}}): Regular Partial Differ...
- Regular Patch ({{MathWorld | urlname=RegularPatch | title=Regular Patch}}): Regular Patch
- Regular Pentagon ({{MathWorld | urlname=RegularPentagon | title=Regular Pentagon}}): Regular Pentagon
- Regular Point ({{MathWorld | urlname=RegularPoint | title=Regular Point}}): Regular Point
- Regular Polychoron ({{MathWorld | urlname=RegularPolychoron | title=Regular Polychoron}}): Regular Polychoron
- Regular Polygon ({{MathWorld | urlname=RegularPolygon | title=Regular Polygon}}): Regular Polygon
- Regular Polygon Divisi... ({{MathWorld | urlname=RegularPolygonDivisionbyDiagonals | title=Regular Polygon Divisi...}}): Regular Polygon Divisi...
- Regular Polyhedron ({{MathWorld | urlname=RegularPolyhedron | title=Regular Polyhedron}}): Regular Polyhedron
- Regular Polytope ({{MathWorld | urlname=RegularPolytope | title=Regular Polytope}}): Regular Polytope
- Regular Prime ({{MathWorld | urlname=RegularPrime | title=Regular Prime}}): Regular Prime
- Regular Pyramid ({{MathWorld | urlname=RegularPyramid | title=Regular Pyramid}}): Regular Pyramid
- Regular Rational Function ({{MathWorld | urlname=RegularRationalFunction | title=Regular Rational Function}}): Regular Rational Function
- Regular Ring ({{MathWorld | urlname=RegularRing | title=Regular Ring}}): Regular Ring
- Regular Sequence ({{MathWorld | urlname=RegularSequence | title=Regular Sequence}}): Regular Sequence
- Regular Singularity ({{MathWorld | urlname=RegularSingularity | title=Regular Singularity}}): Regular Singularity
- Regular Singular Point ({{MathWorld | urlname=RegularSingularPoint | title=Regular Singular Point}}): Regular Singular Point
- Regular Skew Polyhedron ({{MathWorld | urlname=RegularSkewPolyhedron | title=Regular Skew Polyhedron}}): Regular Skew Polyhedron
- Regular Space ({{MathWorld | urlname=RegularSpace | title=Regular Space}}): Regular Space
- Regular Surface ({{MathWorld | urlname=RegularSurface | title=Regular Surface}}): Regular Surface
- Regular Tessellation ({{MathWorld | urlname=RegularTessellation | title=Regular Tessellation}}): Regular Tessellation
- Regular Tetradecagon ({{MathWorld | urlname=RegularTetradecagon | title=Regular Tetradecagon}}): Regular Tetradecagon
- Regular Triangle Center ({{MathWorld | urlname=RegularTriangleCenter | title=Regular Triangle Center}}): Regular Triangle Center
- Regular Tridecagon ({{MathWorld | urlname=RegularTridecagon | title=Regular Tridecagon}}): Regular Tridecagon
- Regular Undecagon ({{MathWorld | urlname=RegularUndecagon | title=Regular Undecagon}}): Regular Undecagon
- Regular Variation ({{MathWorld | urlname=RegularVariation | title=Regular Variation}}): Regular Variation
- Regulator ({{MathWorld | urlname=Regulator | title=Regulator}}): Regulator
- Regulus ({{MathWorld | urlname=Regulus | title=Regulus}}): Regulus
- Reidemeister Moves ({{MathWorld | urlname=ReidemeisterMoves | title=Reidemeister Moves}}): Reidemeister Moves
- Reidemeister's Theorem ({{MathWorld | urlname=ReidemeistersTheorem | title=Reidemeister's Theorem}}): Reidemeister's Theorem
- Reinhardt Domain ({{MathWorld | urlname=ReinhardtDomain | title=Reinhardt Domain}}): Reinhardt Domain
- Relation ({{MathWorld | urlname=Relation | title=Relation}}): Relation
- Relational System ({{MathWorld | urlname=RelationalSystem | title=Relational System}}): Relational System
- Relative Cumulative Fr... ({{MathWorld | urlname=RelativeCumulativeFrequency | title=Relative Cumulative Fr...}}): Relative Cumulative Fr...
- Relative Degree ({{MathWorld | urlname=RelativeDegree | title=Relative Degree}}): Relative Degree
- Relative Deviation ({{MathWorld | urlname=RelativeDeviation | title=Relative Deviation}}): Relative Deviation
- Relative Entropy ({{MathWorld | urlname=RelativeEntropy | title=Relative Entropy}}): Relative Entropy
- Relative Error ({{MathWorld | urlname=RelativeError | title=Relative Error}}): Relative Error
- Relative Extremum ({{MathWorld | urlname=RelativeExtremum | title=Relative Extremum}}): Relative Extremum
- Relative Frequency ({{MathWorld | urlname=RelativeFrequency | title=Relative Frequency}}): Relative Frequency
- Relative Homotopy Group ({{MathWorld | urlname=RelativeHomotopyGroup | title=Relative Homotopy Group}}): Relative Homotopy Group
- Relatively Prime ({{MathWorld | urlname=RelativelyPrime | title=Relatively Prime}}): Relatively Prime
- Relative Maximum ({{MathWorld | urlname=RelativeMaximum | title=Relative Maximum}}): Relative Maximum
- Relative Minimum ({{MathWorld | urlname=RelativeMinimum | title=Relative Minimum}}): Relative Minimum
- Relative Topology ({{MathWorld | urlname=RelativeTopology | title=Relative Topology}}): Relative Topology
- Relaxation Methods ({{MathWorld | urlname=RelaxationMethods | title=Relaxation Methods}}): Relaxation Methods
- Reliability Polynomial ({{MathWorld | urlname=ReliabilityPolynomial | title=Reliability Polynomial}}): Reliability Polynomial
- Remainder ({{MathWorld | urlname=Remainder | title=Remainder}}): Remainder
- Remainder Theorem ({{MathWorld | urlname=RemainderTheorem | title=Remainder Theorem}}): Remainder Theorem
- Rembs' Surface ({{MathWorld | urlname=RembsSurface | title=Rembs' Surface}}): Rembs' Surface
- Remes Algorithm ({{MathWorld | urlname=RemesAlgorithm | title=Remes Algorithm}}): Remes Algorithm
- Remez Algorithm ({{MathWorld | urlname=RemezAlgorithm | title=Remez Algorithm}}): Remez Algorithm
- Remez Exchange Algorithm ({{MathWorld | urlname=RemezExchangeAlgorithm | title=Remez Exchange Algorithm}}): Remez Exchange Algorithm
- Removable Crossing ({{MathWorld | urlname=RemovableCrossing | title=Removable Crossing}}): Removable Crossing
- Removable Singularity ({{MathWorld | urlname=RemovableSingularity | title=Removable Singularity}}): Removable Singularity
- Rencontres Number ({{MathWorld | urlname=RencontresNumber | title=Rencontres Number}}): Rencontres Number
- Rendezvous Values ({{MathWorld | urlname=RendezvousValues | title=Rendezvous Values}}): Rendezvous Values
- Rényi Entropy ({{MathWorld | urlname=RenyiEntropy | title=Rényi Entropy}}): Rényi Entropy
- Rényi Information ({{MathWorld | urlname=RenyiInformation | title=Rényi Information}}): Rényi Information
- Rényi's Parking Constants ({{MathWorld | urlname=RenyisParkingConstants | title=Rényi's Parking Constants}}): Rényi's Parking Constants
- Rényi's Polynomial ({{MathWorld | urlname=RenyisPolynomial | title=Rényi's Polynomial}}): Rényi's Polynomial
- Reparameterization ({{MathWorld | urlname=Reparameterization | title=Reparameterization}}): Reparameterization
- Reparametrization ({{MathWorld | urlname=Reparametrization | title=Reparametrization}}): Reparametrization
- Repartition ({{MathWorld | urlname=Repartition | title=Repartition}}): Repartition
- Repdigit ({{MathWorld | urlname=Repdigit | title=Repdigit}}): Repdigit
- Repeated Fraction ({{MathWorld | urlname=RepeatedFraction | title=Repeated Fraction}}): Repeated Fraction
- Repeated Integral ({{MathWorld | urlname=RepeatedIntegral | title=Repeated Integral}}): Repeated Integral
- Repeated Root ({{MathWorld | urlname=RepeatedRoot | title=Repeated Root}}): Repeated Root
- Repeating Decimal ({{MathWorld | urlname=RepeatingDecimal | title=Repeating Decimal}}): Repeating Decimal
- Repfigit Number ({{MathWorld | urlname=RepfigitNumber | title=Repfigit Number}}): Repfigit Number
- Replicate ({{MathWorld | urlname=Replicate | title=Replicate}}): Replicate
- Replicating Symbol ({{MathWorld | urlname=ReplicatingSymbol | title=Replicating Symbol}}): Replicating Symbol
- Representation ({{MathWorld | urlname=Representation | title=Representation}}): Representation
- Representation Ring ({{MathWorld | urlname=RepresentationRing | title=Representation Ring}}): Representation Ring
- Representation Tensor... ({{MathWorld | urlname=RepresentationTensorProduct | title=Representation Tensor...}}): Representation Tensor...
- Representation Theory ({{MathWorld | urlname=RepresentationTheory | title=Representation Theory}}): Representation Theory
- Represented As ({{MathWorld | urlname=RepresentedAs | title=Represented As}}): Represented As
- Reptend Prime ({{MathWorld | urlname=ReptendPrime | title=Reptend Prime}}): Reptend Prime
- Reptile ({{MathWorld | urlname=Reptile | title=Reptile}}): Reptile
- Rep-Tile ({{MathWorld | urlname=Rep-Tile | title=Rep-Tile}}): Rep-Tile
- Repunit ({{MathWorld | urlname=Repunit | title=Repunit}}): Repunit
- Resampling Statistics ({{MathWorld | urlname=ResamplingStatistics | title=Resampling Statistics}}): Resampling Statistics
- Residual ({{MathWorld | urlname=Residual | title=Residual}}): Residual
- Residual Entropy for S... ({{MathWorld | urlname=ResidualEntropyforSquareIce | title=Residual Entropy for S...}}): Residual Entropy for S...
- Residual Set ({{MathWorld | urlname=ResidualSet | title=Residual Set}}): Residual Set
- Residual vs. Predictor... ({{MathWorld | urlname=ResidualvsPredictorPlot | title=Residual vs. Predictor...}}): Residual vs. Predictor...
- Residue ({{MathWorld | urlname=Residue | title=Residue}}): Residue
- Residue Class ({{MathWorld | urlname=ResidueClass | title=Residue Class}}): Residue Class
- Residue Field ({{MathWorld | urlname=ResidueField | title=Residue Field}}): Residue Field
- Residue Index ({{MathWorld | urlname=ResidueIndex | title=Residue Index}}): Residue Index
- Residue System ({{MathWorld | urlname=ResidueSystem | title=Residue System}}): Residue System
- Residue Theorem ({{MathWorld | urlname=ResidueTheorem | title=Residue Theorem}}): Residue Theorem
- Resistance ({{MathWorld | urlname=Resistance | title=Resistance}}): Resistance
- Resistance Distance ({{MathWorld | urlname=ResistanceDistance | title=Resistance Distance}}): Resistance Distance
- Resistance-Equivalent... ({{MathWorld | urlname=Resistance-EquivalentGraphs | title=Resistance-Equivalent...}}): Resistance-Equivalent...
- Resistance Spectrum ({{MathWorld | urlname=ResistanceSpectrum | title=Resistance Spectrum}}): Resistance Spectrum
- Resistor Network ({{MathWorld | urlname=ResistorNetwork | title=Resistor Network}}): Resistor Network
- Resolution ({{MathWorld | urlname=Resolution | title=Resolution}}): Resolution
- Resolution Class ({{MathWorld | urlname=ResolutionClass | title=Resolution Class}}): Resolution Class
- Resolution Modulus ({{MathWorld | urlname=ResolutionModulus | title=Resolution Modulus}}): Resolution Modulus
- Resolution Principle ({{MathWorld | urlname=ResolutionPrinciple | title=Resolution Principle}}): Resolution Principle
- Resolvable ({{MathWorld | urlname=Resolvable | title=Resolvable}}): Resolvable
- Resolve ({{MathWorld | urlname=Resolve | title=Resolve}}): Resolve
- Resolvent ({{MathWorld | urlname=Resolvent | title=Resolvent}}): Resolvent
- Resolvent Cubic ({{MathWorld | urlname=ResolventCubic | title=Resolvent Cubic}}): Quartic equation#Galois theory and factorization
- Resolving Tree ({{MathWorld | urlname=ResolvingTree | title=Resolving Tree}}): Resolving Tree
- Resonance Overlap ({{MathWorld | urlname=ResonanceOverlap | title=Resonance Overlap}}): Resonance Overlap
- Resonance Overlap Method ({{MathWorld | urlname=ResonanceOverlapMethod | title=Resonance Overlap Method}}): Resonance Overlap Method
- R-Estimate ({{MathWorld | urlname=R-Estimate | title=R-Estimate}}): R-Estimate
- Restricted Divisor Fun... ({{MathWorld | urlname=RestrictedDivisorFunction | title=Restricted Divisor Fun...}}): Restricted Divisor Fun...
- Restricted Growth Func... ({{MathWorld | urlname=RestrictedGrowthFunction | title=Restricted Growth Func...}}): Restricted Growth Func...
- Restricted Growth String ({{MathWorld | urlname=RestrictedGrowthString | title=Restricted Growth String}}): Restricted Growth String
- Resultant ({{MathWorld | urlname=Resultant | title=Resultant}}): Resultant
- Retardance ({{MathWorld | urlname=Retardance | title=Retardance}}): Retardance
- Retract ({{MathWorld | urlname=Retract | title=Retract}}): Retract
- Retraction ({{MathWorld | urlname=Retraction | title=Retraction}}): Retraction
- Reuleaux Polygon ({{MathWorld | urlname=ReuleauxPolygon | title=Reuleaux Polygon}}): Reuleaux Polygon
- Reuleaux Tetrahedron ({{MathWorld | urlname=ReuleauxTetrahedron | title=Reuleaux Tetrahedron}}): Reuleaux Tetrahedron
- Reuleaux Triangle ({{MathWorld | urlname=ReuleauxTriangle | title=Reuleaux Triangle}}): Reuleaux Triangle
- Reverend Back's Abbey... ({{MathWorld | urlname=ReverendBacksAbbeyFloor | title=Reverend Back's Abbey...}}): Reverend Back's Abbey...
- Reversal ({{MathWorld | urlname=Reversal | title=Reversal}}): Reversal
- Reverse Greedy Algorithm ({{MathWorld | urlname=ReverseGreedyAlgorithm | title=Reverse Greedy Algorithm}}): Reverse Greedy Algorithm
- Reverse Polish Notation ({{MathWorld | urlname=ReversePolishNotation | title=Reverse Polish Notation}}): Reverse Polish Notation
- Reverse-Then-Add Sequence ({{MathWorld | urlname=Reverse-Then-AddSequence | title=Reverse-Then-Add Sequence}}): Reverse-Then-Add Sequence
- Reversible Goblet ({{MathWorld | urlname=ReversibleGoblet | title=Reversible Goblet}}): Reversible Goblet
- Reversible Knot ({{MathWorld | urlname=ReversibleKnot | title=Reversible Knot}}): Reversible Knot
- Reversible Prime ({{MathWorld | urlname=ReversiblePrime | title=Reversible Prime}}): Reversible Prime
- Reversion of Series ({{MathWorld | urlname=ReversionofSeries | title=Reversion of Series}}): Reversion of Series
- Reversion to the Mean ({{MathWorld | urlname=ReversiontotheMean | title=Reversion to the Mean}}): Reversion to the Mean
- Reve's Puzzle ({{MathWorld | urlname=RevesPuzzle | title=Reve's Puzzle}}): Reve's Puzzle
- Revrepfigit Number ({{MathWorld | urlname=RevrepfigitNumber | title=Revrepfigit Number}}): Revrepfigit Number
- Rewriting System ({{MathWorld | urlname=RewritingSystem | title=Rewriting System}}): Rewriting System
- Reye Configuration ({{MathWorld | urlname=ReyeConfiguration | title=Reye Configuration}}): Reye Configuration
- Reye Graph ({{MathWorld | urlname=ReyeGraph | title=Reye Graph}}): Reye Graph
- Reznick's Identity ({{MathWorld | urlname=ReznicksIdentity | title=Reznick's Identity}}): Reznick's Identity
- R Graph ({{MathWorld | urlname=RGraph | title=R Graph}}): R Graph
- Rhind Papyrus ({{MathWorld | urlname=RhindPapyrus | title=Rhind Papyrus}}): Rhind Papyrus
- Rhodonea ({{MathWorld | urlname=Rhodonea | title=Rhodonea}}): Rhodonea
- Rhomb ({{MathWorld | urlname=Rhomb | title=Rhomb}}): Rhomb
- Rhombic Dodecahedral G... ({{MathWorld | urlname=RhombicDodecahedralGraph | title=Rhombic Dodecahedral G...}}): Rhombic Dodecahedral G...
- Rhombic Dodecahedral N... ({{MathWorld | urlname=RhombicDodecahedralNumber | title=Rhombic Dodecahedral N...}}): Rhombic Dodecahedral N...
- Rhombic Dodecahedron ({{MathWorld | urlname=RhombicDodecahedron | title=Rhombic Dodecahedron}}): Rhombic Dodecahedron
- Rhombic Dodecahedron S... ({{MathWorld | urlname=RhombicDodecahedronStellations | title=Rhombic Dodecahedron S...}}): Rhombic Dodecahedron S...
- Rhombic Enneacontahedron ({{MathWorld | urlname=RhombicEnneacontahedron | title=Rhombic Enneacontahedron}}): Rhombic Enneacontahedron
- Rhombic Hexecontahedron ({{MathWorld | urlname=RhombicHexecontahedron | title=Rhombic Hexecontahedron}}): Rhombic Hexecontahedron
- Rhombic Icosahedron ({{MathWorld | urlname=RhombicIcosahedron | title=Rhombic Icosahedron}}): Rhombic Icosahedron
- Rhombicosacron ({{MathWorld | urlname=Rhombicosacron | title=Rhombicosacron}}): Rhombicosacron
- Rhombicosahedron ({{MathWorld | urlname=Rhombicosahedron | title=Rhombicosahedron}}): Rhombicosahedron
- Rhombicosidodecahedron ({{MathWorld | urlname=Rhombicosidodecahedron | title=Rhombicosidodecahedron}}): Rhombicosidodecahedron
- Rhombic Polyhedron ({{MathWorld | urlname=RhombicPolyhedron | title=Rhombic Polyhedron}}): Rhombic Polyhedron
- Rhombic Spirallohedron ({{MathWorld | urlname=RhombicSpirallohedron | title=Rhombic Spirallohedron}}): Rhombic Spirallohedron
- Rhombic Triacontahedra... ({{MathWorld | urlname=RhombicTriacontahedralGraph | title=Rhombic Triacontahedra...}}): Rhombic Triacontahedra...
- Rhombic Triacontahedron ({{MathWorld | urlname=RhombicTriacontahedron | title=Rhombic Triacontahedron}}): Rhombic Triacontahedron
- Rhombic Triacontahedro... ({{MathWorld | urlname=RhombicTriacontahedronStellations | title=Rhombic Triacontahedro...}}): Rhombic Triacontahedro...
- Rhombicuboctahedron ({{MathWorld | urlname=Rhombicuboctahedron | title=Rhombicuboctahedron}}): Rhombicuboctahedron
- Rhombidodecadodecahedron ({{MathWorld | urlname=Rhombidodecadodecahedron | title=Rhombidodecadodecahedron}}): Rhombidodecadodecahedron
- Rhombihexacron ({{MathWorld | urlname=Rhombihexacron | title=Rhombihexacron}}): Rhombihexacron
- Rhombihexahedron ({{MathWorld | urlname=Rhombihexahedron | title=Rhombihexahedron}}): Rhombihexahedron
- Rhombitruncated Cuboct... ({{MathWorld | urlname=RhombitruncatedCuboctahedron | title=Rhombitruncated Cuboct...}}): Rhombitruncated Cuboct...
- Rhombitruncated Icosid... ({{MathWorld | urlname=RhombitruncatedIcosidodecahedron | title=Rhombitruncated Icosid...}}): Rhombitruncated Icosid...
- Rhombohedron ({{MathWorld | urlname=Rhombohedron | title=Rhombohedron}}): Rhombohedron
- Rhombo-Hexagonal Dodec... ({{MathWorld | urlname=Rhombo-HexagonalDodecahedron | title=Rhombo-Hexagonal Dodec...}}): Rhombo-Hexagonal Dodec...
- Rhomboid ({{MathWorld | urlname=Rhomboid | title=Rhomboid}}): Rhomboid
- Rhomboidal Dodecahedron ({{MathWorld | urlname=RhomboidalDodecahedron | title=Rhomboidal Dodecahedron}}): Rhomboidal Dodecahedron
- Rhombus ({{MathWorld | urlname=Rhombus | title=Rhombus}}): Rhombus
- Rhombus Algorithm ({{MathWorld | urlname=RhombusAlgorithm | title=Rhombus Algorithm}}): Rhombus Algorithm
- Rhonda Number ({{MathWorld | urlname=RhondaNumber | title=Rhonda Number}}): Rhonda Number
- Rhumb Line ({{MathWorld | urlname=RhumbLine | title=Rhumb Line}}): Rhumb Line
- Ribbon Knot ({{MathWorld | urlname=RibbonKnot | title=Ribbon Knot}}): Ribbon Knot
- Ribet's Theorem ({{MathWorld | urlname=RibetsTheorem | title=Ribet's Theorem}}): Ribet's Theorem
- Riccati-Bessel Functions ({{MathWorld | urlname=Riccati-BesselFunctions | title=Riccati-Bessel Functions}}): Riccati-Bessel Functions
- Riccati Differential E... ({{MathWorld | urlname=RiccatiDifferentialEquation | title=Riccati Differential E...}}): Riccati Differential E...
- Ricci Curvature ({{MathWorld | urlname=RicciCurvature | title=Ricci Curvature}}): Ricci Curvature
- Ricci Curvature Tensor ({{MathWorld | urlname=RicciCurvatureTensor | title=Ricci Curvature Tensor}}): Ricci Curvature Tensor
- Ricci Flow ({{MathWorld | urlname=RicciFlow | title=Ricci Flow}}): Ricci Flow
- Ricci Tensor ({{MathWorld | urlname=RicciTensor | title=Ricci Tensor}}): Ricci Tensor
- Rice Distribution ({{MathWorld | urlname=RiceDistribution | title=Rice Distribution}}): Rice Distribution
- Rice's Theorem ({{MathWorld | urlname=RicesTheorem | title=Rice's Theorem}}): Rice's Theorem
- Richardson Effect ({{MathWorld | urlname=RichardsonEffect | title=Richardson Effect}}): Richardson Effect
- Richardson Extrapolation ({{MathWorld | urlname=RichardsonExtrapolation | title=Richardson Extrapolation}}): Richardson Extrapolation
- Richardson's Theorem ({{MathWorld | urlname=RichardsonsTheorem | title=Richardson's Theorem}}): Richardson's Theorem
- Richard's Paradox ({{MathWorld | urlname=RichardsParadox | title=Richard's Paradox}}): Richard's Paradox
- Riddell's Formula ({{MathWorld | urlname=RiddellsFormula | title=Riddell's Formula}}): Riddell's Formula
- Ridders' Method ({{MathWorld | urlname=RiddersMethod | title=Ridders' Method}}): Ridders' Method
- Ridge ({{MathWorld | urlname=Ridge | title=Ridge}}): Ridge
- Riemann-Christoffel Cu... ({{MathWorld | urlname=Riemann-ChristoffelCurvatureTensor | title=Riemann-Christoffel Cu...}}): Riemann-Christoffel Cu...
- Riemann-Christoffel Te... ({{MathWorld | urlname=Riemann-ChristoffelTensor | title=Riemann-Christoffel Te...}}): Riemann-Christoffel Te...
- Riemann Curvature Tensor ({{MathWorld | urlname=RiemannCurvatureTensor | title=Riemann Curvature Tensor}}): Riemann Curvature Tensor
- Riemann Curve Theorem ({{MathWorld | urlname=RiemannCurveTheorem | title=Riemann Curve Theorem}}): Riemann Curve Theorem
- Riemann Differential E... ({{MathWorld | urlname=RiemannDifferentialEquation | title=Riemann Differential E...}}): Riemann Differential E...
- Riemann-Finsler Geometry ({{MathWorld | urlname=Riemann-FinslerGeometry | title=Riemann-Finsler Geometry}}): Riemann-Finsler Geometry
- Riemann Formula ({{MathWorld | urlname=RiemannFormula | title=Riemann Formula}}): Riemann Formula
- Riemann Function ({{MathWorld | urlname=RiemannFunction | title=Riemann Function}}): Riemann Function
- Riemann-Hurwitz Formula ({{MathWorld | urlname=Riemann-HurwitzFormula | title=Riemann-Hurwitz Formula}}): Riemann-Hurwitz Formula
- Riemann Hypothesis ({{MathWorld | urlname=RiemannHypothesis | title=Riemann Hypothesis}}): Riemann Hypothesis
- Riemannian Geometry ({{MathWorld | urlname=RiemannianGeometry | title=Riemannian Geometry}}): Riemannian Geometry
- Riemannian Manifold ({{MathWorld | urlname=RiemannianManifold | title=Riemannian Manifold}}): Riemannian Manifold
- Riemannian Metric ({{MathWorld | urlname=RiemannianMetric | title=Riemannian Metric}}): Riemannian Metric
- Riemannian Submersion ({{MathWorld | urlname=RiemannianSubmersion | title=Riemannian Submersion}}): Riemannian Submersion
- Riemann Integral ({{MathWorld | urlname=RiemannIntegral | title=Riemann Integral}}): Riemann Integral
- Riemann-Lebesgue Lemma ({{MathWorld | urlname=Riemann-LebesgueLemma | title=Riemann-Lebesgue Lemma}}): Riemann-Lebesgue Lemma
- Riemann-Liouville Oper... ({{MathWorld | urlname=Riemann-LiouvilleOperator | title=Riemann-Liouville Oper...}}): Riemann-Liouville Oper...
- Riemann Mapping Theorem ({{MathWorld | urlname=RiemannMappingTheorem | title=Riemann Mapping Theorem}}): Riemann Mapping Theorem
- Riemann Method ({{MathWorld | urlname=RiemannMethod | title=Riemann Method}}): Riemann Method
- Riemann P-Differential... ({{MathWorld | urlname=RiemannP-DifferentialEquation | title=Riemann P-Differential...}}): Riemann P-Differential...
- Riemann P-Function ({{MathWorld | urlname=RiemannP-Function | title=Riemann P-Function}}): Riemann P-Function
- Riemann Prime Counting... ({{MathWorld | urlname=RiemannPrimeCountingFunction | title=Riemann Prime Counting...}}): Riemann Prime Counting...
- Riemann Prime Number F... ({{MathWorld | urlname=RiemannPrimeNumberFormula | title=Riemann Prime Number F...}}): Riemann Prime Number F...
- Riemann P-Series ({{MathWorld | urlname=RiemannP-Series | title=Riemann P-Series}}): Riemann P-Series
- RiemannR ({{MathWorld | urlname=RiemannR | title=RiemannR}}): RiemannR
- Riemann Removable Sing... ({{MathWorld | urlname=RiemannRemovableSingularityTheorem | title=Riemann Removable Sing...}}): Riemann Removable Sing...
- Riemann-Roch Theorem ({{MathWorld | urlname=Riemann-RochTheorem | title=Riemann-Roch Theorem}}): Riemann-Roch Theorem
- Riemann Series Theorem ({{MathWorld | urlname=RiemannSeriesTheorem | title=Riemann Series Theorem}}): Riemann Series Theorem
- Riemann-Siegel Formula ({{MathWorld | urlname=Riemann-SiegelFormula | title=Riemann-Siegel Formula}}): Riemann-Siegel Formula
- Riemann-Siegel Functions ({{MathWorld | urlname=Riemann-SiegelFunctions | title=Riemann-Siegel Functions}}): Riemann-Siegel Functions
- Riemann-Siegel Integra... ({{MathWorld | urlname=Riemann-SiegelIntegralFormula | title=Riemann-Siegel Integra...}}): Riemann-Siegel Integra...
- RiemannSiegelTheta ({{MathWorld | urlname=RiemannSiegelTheta | title=RiemannSiegelTheta}}): RiemannSiegelTheta
- RiemannSiegelZ ({{MathWorld | urlname=RiemannSiegelZ | title=RiemannSiegelZ}}): RiemannSiegelZ
- Riemann's Integral The... ({{MathWorld | urlname=RiemannsIntegralTheorem | title=Riemann's Integral The...}}): Riemann's Integral The...
- Riemann's Moduli Problem ({{MathWorld | urlname=RiemannsModuliProblem | title=Riemann's Moduli Problem}}): Riemann's Moduli Problem
- Riemann's Moduli Space ({{MathWorld | urlname=RiemannsModuliSpace | title=Riemann's Moduli Space}}): Riemann's Moduli Space
- Riemann's Nondifferent... ({{MathWorld | urlname=RiemannsNondifferentiableFunction | title=Riemann's Nondifferent...}}): Riemann's Nondifferent...
- Riemann Space ({{MathWorld | urlname=RiemannSpace | title=Riemann Space}}): Riemann Space
- Riemann Sphere ({{MathWorld | urlname=RiemannSphere | title=Riemann Sphere}}): Riemann Sphere
- Riemann Sphere Place ({{MathWorld | urlname=RiemannSpherePlace | title=Riemann Sphere Place}}): Riemann Sphere Place
- Riemann-Stieltjes Inte... ({{MathWorld | urlname=Riemann-StieltjesIntegral | title=Riemann-Stieltjes Inte...}}): Riemann-Stieltjes Inte...
- Riemann Sum ({{MathWorld | urlname=RiemannSum | title=Riemann Sum}}): Riemann Sum
- Riemann Surface ({{MathWorld | urlname=RiemannSurface | title=Riemann Surface}}): Riemann Surface
- Riemann Tensor ({{MathWorld | urlname=RiemannTensor | title=Riemann Tensor}}): Riemann Tensor
- Riemann Theta Function ({{MathWorld | urlname=RiemannThetaFunction | title=Riemann Theta Function}}): Riemann Theta Function
- Riemann-Volterra Method ({{MathWorld | urlname=Riemann-VolterraMethod | title=Riemann-Volterra Method}}): Riemann-Volterra Method
- Riemann-von Mangoldt F... ({{MathWorld | urlname=Riemann-vonMangoldtFormula | title=Riemann-von Mangoldt F...}}): Riemann-von Mangoldt F...
- Riemann Xi-Function ({{MathWorld | urlname=RiemannXi-Function | title=Riemann Xi-Function}}): Riemann Xi-Function
- Riemann Zeta Function ({{MathWorld | urlname=RiemannZetaFunction | title=Riemann Zeta Function}}): Riemann Zeta Function
- Riemann Zeta Function... ({{MathWorld | urlname=RiemannZetaFunctionZeros | title=Riemann Zeta Function...}}): Riemann Zeta Function...
- Riemann Zeta Function... ({{MathWorld | urlname=RiemannZetaFunctionZeta2 | title=Riemann Zeta Function...}}): Riemann Zeta Function...
- Riemann Zeta Function... ({{MathWorld | urlname=RiemannZetaFunctionZeta3 | title=Riemann Zeta Function...}}): Riemann Zeta Function...
- Riesel Conjecture ({{MathWorld | urlname=RieselConjecture | title=Riesel Conjecture}}): Riesel Conjecture
- Riesel Number ({{MathWorld | urlname=RieselNumber | title=Riesel Number}}): Riesel Number
- Riesel Problem ({{MathWorld | urlname=RieselProblem | title=Riesel Problem}}): Riesel Problem
- Riesz-Fischer Theorem ({{MathWorld | urlname=Riesz-FischerTheorem | title=Riesz-Fischer Theorem}}): Riesz-Fischer Theorem
- Riesz Representation T... ({{MathWorld | urlname=RieszRepresentationTheorem | title=Riesz Representation T...}}): Riesz Representation T...
- Riesz-Schauder Theory ({{MathWorld | urlname=Riesz-SchauderTheory | title=Riesz-Schauder Theory}}): Riesz-Schauder Theory
- Riesz's Theorem ({{MathWorld | urlname=RieszsTheorem | title=Riesz's Theorem}}): Riesz's Theorem
- Riffle ({{MathWorld | urlname=Riffle | title=Riffle}}): Riffle
- Riffle Shuffle ({{MathWorld | urlname=RiffleShuffle | title=Riffle Shuffle}}): Riffle Shuffle
- Rigby Points ({{MathWorld | urlname=RigbyPoints | title=Rigby Points}}): Rigby Points
- Rigged Hilbert Space ({{MathWorld | urlname=RiggedHilbertSpace | title=Rigged Hilbert Space}}): Rigged Hilbert Space
- Right Angle ({{MathWorld | urlname=RightAngle | title=Right Angle}}): Right Angle
- Right Circular Cone ({{MathWorld | urlname=RightCircularCone | title=Right Circular Cone}}): Right Circular Cone
- Right Circular Cylinder ({{MathWorld | urlname=RightCircularCylinder | title=Right Circular Cylinder}}): Right Circular Cylinder
- Right Cone ({{MathWorld | urlname=RightCone | title=Right Cone}}): Right Cone
- Right Conoid ({{MathWorld | urlname=RightConoid | title=Right Conoid}}): Right Conoid
- Right Coset ({{MathWorld | urlname=RightCoset | title=Right Coset}}): Right Coset
- Right Cylinder ({{MathWorld | urlname=RightCylinder | title=Right Cylinder}}): Right Cylinder
- Right Eigenvector ({{MathWorld | urlname=RightEigenvector | title=Right Eigenvector}}): Right Eigenvector
- Right Half-Plane ({{MathWorld | urlname=RightHalf-Plane | title=Right Half-Plane}}): Right Half-Plane
- Right-Handed Coordinat... ({{MathWorld | urlname=Right-HandedCoordinateSystem | title=Right-Handed Coordinat...}}): Right-Handed Coordinat...
- Right-Hand Rule ({{MathWorld | urlname=Right-HandRule | title=Right-Hand Rule}}): Right-Hand Rule
- Right Hyperbola ({{MathWorld | urlname=RightHyperbola | title=Right Hyperbola}}): Right Hyperbola
- Right Ideal ({{MathWorld | urlname=RightIdeal | title=Right Ideal}}): Right Ideal
- Right Inverse ({{MathWorld | urlname=RightInverse | title=Right Inverse}}): Right Inverse
- Right Isosceles Triangle ({{MathWorld | urlname=RightIsoscelesTriangle | title=Right Isosceles Triangle}}): Right Isosceles Triangle
- Right Line ({{MathWorld | urlname=RightLine | title=Right Line}}): Right Line
- Right Lip Continuity ({{MathWorld | urlname=RightLipContinuity | title=Right Lip Continuity}}): Right Lip Continuity
- Right Prism ({{MathWorld | urlname=RightPrism | title=Right Prism}}): Right Prism
- Right Pyramid ({{MathWorld | urlname=RightPyramid | title=Right Pyramid}}): Right Pyramid
- Right Strophoid ({{MathWorld | urlname=RightStrophoid | title=Right Strophoid}}): Right Strophoid
- Right Strophoid Invers... ({{MathWorld | urlname=RightStrophoidInverseCurve | title=Right Strophoid Invers...}}): Right Strophoid Invers...
- Right Transversal ({{MathWorld | urlname=RightTransversal | title=Right Transversal}}): Right Transversal
- Right Triangle ({{MathWorld | urlname=RightTriangle | title=Right Triangle}}): Right Triangle
- Rigid Framework ({{MathWorld | urlname=RigidFramework | title=Rigid Framework}}): Rigid Framework
- Rigid Graph ({{MathWorld | urlname=RigidGraph | title=Rigid Graph}}): Rigid Graph
- Rigidity Theorem ({{MathWorld | urlname=RigidityTheorem | title=Rigidity Theorem}}): Rigidity Theorem
- Rigid Motion ({{MathWorld | urlname=RigidMotion | title=Rigid Motion}}): Rigid Motion
- Rigid Polyhedron ({{MathWorld | urlname=RigidPolyhedron | title=Rigid Polyhedron}}): Rigid Polyhedron
- Rigorous ({{MathWorld | urlname=Rigorous | title=Rigorous}}): Rigorous
- Ring ({{MathWorld | urlname=Ring | title=Ring}}): Ring
- Ring Cyclide ({{MathWorld | urlname=RingCyclide | title=Ring Cyclide}}): Ring Cyclide
- Ring Direct Product ({{MathWorld | urlname=RingDirectProduct | title=Ring Direct Product}}): Ring Direct Product
- Ring Extension ({{MathWorld | urlname=RingExtension | title=Ring Extension}}): Ring Extension
- Ring Function ({{MathWorld | urlname=RingFunction | title=Ring Function}}): Ring Function
- Ring Homomorphism ({{MathWorld | urlname=RingHomomorphism | title=Ring Homomorphism}}): Ring Homomorphism
- Ring Isomorphism Theorems ({{MathWorld | urlname=RingIsomorphismTheorems | title=Ring Isomorphism Theorems}}): Ring Isomorphism Theorems
- Ring Kernel ({{MathWorld | urlname=RingKernel | title=Ring Kernel}}): Ring Kernel
- Ring of Fractions ({{MathWorld | urlname=RingofFractions | title=Ring of Fractions}}): Ring of Fractions
- Ring of Integers ({{MathWorld | urlname=RingofIntegers | title=Ring of Integers}}): Ring of Integers
- Ring of Polynomials ({{MathWorld | urlname=RingofPolynomials | title=Ring of Polynomials}}): Ring of Polynomials
- Ringoid ({{MathWorld | urlname=Ringoid | title=Ringoid}}): Ringoid
- Ring Regular Sequence ({{MathWorld | urlname=RingRegularSequence | title=Ring Regular Sequence}}): Ring Regular Sequence
- Ring Spectrum ({{MathWorld | urlname=RingSpectrum | title=Ring Spectrum}}): Ring Spectrum
- Ring Theory ({{MathWorld | urlname=RingTheory | title=Ring Theory}}): Ring Theory
- Ring Torus ({{MathWorld | urlname=RingTorus | title=Ring Torus}}): Ring Torus
- Ring Unit ({{MathWorld | urlname=RingUnit | title=Ring Unit}}): Ring Unit
- Ring with Identity ({{MathWorld | urlname=RingwithIdentity | title=Ring with Identity}}): Ring with Identity
- Risch Algorithm ({{MathWorld | urlname=RischAlgorithm | title=Risch Algorithm}}): Risch Algorithm
- Rise ({{MathWorld | urlname=Rise | title=Rise}}): Rise
- Rising Factorial ({{MathWorld | urlname=RisingFactorial | title=Rising Factorial}}): Rising Factorial
- Rising Factorial Power ({{MathWorld | urlname=RisingFactorialPower | title=Rising Factorial Power}}): Rising Factorial Power
- Rising Power ({{MathWorld | urlname=RisingPower | title=Rising Power}}): Rising Power
- Rising Sun Graph ({{MathWorld | urlname=RisingSunGraph | title=Rising Sun Graph}}): Rising Sun Graph
- Rivest-Shamir-Adleman... ({{MathWorld | urlname=Rivest-Shamir-AdlemanNumber | title=Rivest-Shamir-Adleman...}}): Rivest-Shamir-Adleman...
- RK2 ({{MathWorld | urlname=RK2 | title=RK2}}): RK2
- RK4 ({{MathWorld | urlname=RK4 | title=RK4}}): RK4
- R-Module ({{MathWorld | urlname=R-Module | title=R-Module}}): R-Module
- RMS ({{MathWorld | urlname=RMS | title=RMS}}): RMS
- Rn ({{MathWorld | urlname=Rn | title=Rn}}): Rn
- Road Coloring Problem ({{MathWorld | urlname=RoadColoringProblem | title=Road Coloring Problem}}): Road Coloring Problem
- Robbins Algebra ({{MathWorld | urlname=RobbinsAlgebra | title=Robbins Algebra}}): Robbins Algebra
- Robbins Axiom ({{MathWorld | urlname=RobbinsAxiom | title=Robbins Axiom}}): Robbins Axiom
- Robbins Conjecture ({{MathWorld | urlname=RobbinsConjecture | title=Robbins Conjecture}}): Robbins Conjecture
- Robbins Constant ({{MathWorld | urlname=RobbinsConstant | title=Robbins Constant}}): Robbins Constant
- Robbin's Inequality ({{MathWorld | urlname=RobbinsInequality | title=Robbin's Inequality}}): Robbin's Inequality
- Robbins-Monro Stochast... ({{MathWorld | urlname=Robbins-MonroStochasticApproximation | title=Robbins-Monro Stochast...}}): Robbins-Monro Stochast...
- Robbins Number ({{MathWorld | urlname=RobbinsNumber | title=Robbins Number}}): Robbins Number
- Robertson Condition ({{MathWorld | urlname=RobertsonCondition | title=Robertson Condition}}): Robertson Condition
- Robertson Conjecture ({{MathWorld | urlname=RobertsonConjecture | title=Robertson Conjecture}}): Robertson Conjecture
- Robertson Graph ({{MathWorld | urlname=RobertsonGraph | title=Robertson Graph}}): Robertson Graph
- Robertson-Seymour Theorem ({{MathWorld | urlname=Robertson-SeymourTheorem | title=Robertson-Seymour Theorem}}): Robertson-Seymour Theorem
- Robertson-Wegner Graph ({{MathWorld | urlname=Robertson-WegnerGraph | title=Robertson-Wegner Graph}}): Robertson-Wegner Graph
- Robin Boundary Conditions ({{MathWorld | urlname=RobinBoundaryConditions | title=Robin Boundary Conditions}}): Robin Boundary Conditions
- Robin's Constant ({{MathWorld | urlname=RobinsConstant | title=Robin's Constant}}): Robin's Constant
- Robinson Projection ({{MathWorld | urlname=RobinsonProjection | title=Robinson Projection}}): Robinson Projection
- Robin's Theorem ({{MathWorld | urlname=RobinsTheorem | title=Robin's Theorem}}): Robin's Theorem
- Robust Estimation ({{MathWorld | urlname=RobustEstimation | title=Robust Estimation}}): Robust Estimation
- Rodrigues' Curvature F... ({{MathWorld | urlname=RodriguesCurvatureFormula | title=Rodrigues' Curvature F...}}): Rodrigues' Curvature F...
- Rodrigues Formula ({{MathWorld | urlname=RodriguesFormula | title=Rodrigues Formula}}): Rodrigues Formula
- Rodrigues Representation ({{MathWorld | urlname=RodriguesRepresentation | title=Rodrigues Representation}}): Rodrigues Representation
- Rodrigues' Rotation Fo... ({{MathWorld | urlname=RodriguesRotationFormula | title=Rodrigues' Rotation Fo...}}): Rodrigues' Rotation Fo...
- Rössler Attractor ({{MathWorld | urlname=RoesslerAttractor | title=Rössler Attractor}}): Rössler Attractor
- Rogers L-Function ({{MathWorld | urlname=RogersL-Function | title=Rogers L-Function}}): Rogers L-Function
- Rogers Mod 14 Identities ({{MathWorld | urlname=RogersMod14Identities | title=Rogers Mod 14 Identities}}): Rogers Mod 14 Identities
- Rogers-Ramanujan Conti... ({{MathWorld | urlname=Rogers-RamanujanContinuedFraction | title=Rogers-Ramanujan Conti...}}): Rogers-Ramanujan Conti...
- Rogers-Ramanujan Ident... ({{MathWorld | urlname=Rogers-RamanujanIdentities | title=Rogers-Ramanujan Ident...}}): Rogers-Ramanujan Ident...
- Rogers-Selberg Identities ({{MathWorld | urlname=Rogers-SelbergIdentities | title=Rogers-Selberg Identities}}): Rogers-Selberg Identities
- Roller ({{MathWorld | urlname=Roller | title=Roller}}): Roller
- Rolle's Theorem ({{MathWorld | urlname=RollesTheorem | title=Rolle's Theorem}}): Rolle's Theorem
- Rolling Polygon ({{MathWorld | urlname=RollingPolygon | title=Rolling Polygon}}): Rolling Polygon
- Roman Coefficient ({{MathWorld | urlname=RomanCoefficient | title=Roman Coefficient}}): Roman Coefficient
- Roman Factorial ({{MathWorld | urlname=RomanFactorial | title=Roman Factorial}}): Roman Factorial
- Roman Numerals ({{MathWorld | urlname=RomanNumerals | title=Roman Numerals}}): Roman Numerals
- Roman Surface ({{MathWorld | urlname=RomanSurface | title=Roman Surface}}): Roman Surface
- Roman Symbol ({{MathWorld | urlname=RomanSymbol | title=Roman Symbol}}): Roman Symbol
- Romberg Integration ({{MathWorld | urlname=RombergIntegration | title=Romberg Integration}}): Romberg Integration
- Rook Number ({{MathWorld | urlname=RookNumber | title=Rook Number}}): Rook Number
- Rook Polynomial ({{MathWorld | urlname=RookPolynomial | title=Rook Polynomial}}): Rook Polynomial
- Rook Reciprocity Theorem ({{MathWorld | urlname=RookReciprocityTheorem | title=Rook Reciprocity Theorem}}): Rook Reciprocity Theorem
- Rooks Problem ({{MathWorld | urlname=RooksProblem | title=Rooks Problem}}): Rooks Problem
- Rook's Tour ({{MathWorld | urlname=RooksTour | title=Rook's Tour}}): Rook's Tour
- Room Square ({{MathWorld | urlname=RoomSquare | title=Room Square}}): Room Square
- Root ({{MathWorld | urlname=Root | title=Root}}): Root
- RootApproximant ({{MathWorld | urlname=RootApproximant | title=RootApproximant}}): RootApproximant
- Root Bracketing ({{MathWorld | urlname=RootBracketing | title=Root Bracketing}}): Root Bracketing
- Root Dragging Theorem ({{MathWorld | urlname=RootDraggingTheorem | title=Root Dragging Theorem}}): Root Dragging Theorem
- Rooted Graph ({{MathWorld | urlname=RootedGraph | title=Rooted Graph}}): Rooted Graph
- Rooted Tree ({{MathWorld | urlname=RootedTree | title=Rooted Tree}}): Rooted Tree
- Root Extraction ({{MathWorld | urlname=RootExtraction | title=Root Extraction}}): Root Extraction
- Root-Finding Algorithm ({{MathWorld | urlname=Root-FindingAlgorithm | title=Root-Finding Algorithm}}): Root-Finding Algorithm
- Root Isolation ({{MathWorld | urlname=RootIsolation | title=Root Isolation}}): Root Isolation
- Root Lattice ({{MathWorld | urlname=RootLattice | title=Root Lattice}}): Root Lattice
- Root Linear Coefficien... ({{MathWorld | urlname=RootLinearCoefficientTheorem | title=Root Linear Coefficien...}}): Root Linear Coefficien...
- Root-Mean-Square ({{MathWorld | urlname=Root-Mean-Square | title=Root-Mean-Square}}): Root-Mean-Square
- Root Node ({{MathWorld | urlname=RootNode | title=Root Node}}): Root Node
- Root of Unity ({{MathWorld | urlname=RootofUnity | title=Root of Unity}}): Root of Unity
- Root Order ({{MathWorld | urlname=RootOrder | title=Root Order}}): Root Order
- Roots ({{MathWorld | urlname=Roots | title=Roots}}): Roots
- Root Separation ({{MathWorld | urlname=RootSeparation | title=Root Separation}}): Root Separation
- Root Space ({{MathWorld | urlname=RootSpace | title=Root Space}}): Root Space
- RootSum ({{MathWorld | urlname=RootSum | title=RootSum}}): RootSum
- Root System ({{MathWorld | urlname=RootSystem | title=Root System}}): Root System
- Root Test ({{MathWorld | urlname=RootTest | title=Root Test}}): Root Test
- Root Vertex ({{MathWorld | urlname=RootVertex | title=Root Vertex}}): Root Vertex
- Rosatti's Theorem ({{MathWorld | urlname=RosattisTheorem | title=Rosatti's Theorem}}): Rosatti's Theorem
- Rose ({{MathWorld | urlname=Rose | title=Rose}}): Rose
- Rosenbrock Function ({{MathWorld | urlname=RosenbrockFunction | title=Rosenbrock Function}}): Rosenbrock Function
- Rosenbrock Methods ({{MathWorld | urlname=RosenbrockMethods | title=Rosenbrock Methods}}): Rosenbrock Methods
- Rosser's Rule ({{MathWorld | urlname=RossersRule | title=Rosser's Rule}}): Rosser's Rule
- Rosser's Theorem ({{MathWorld | urlname=RossersTheorem | title=Rosser's Theorem}}): Rosser's Theorem
- RotateLeft ({{MathWorld | urlname=RotateLeft | title=RotateLeft}}): RotateLeft
- RotateRight ({{MathWorld | urlname=RotateRight | title=RotateRight}}): RotateRight
- Rotating Square Illusion ({{MathWorld | urlname=RotatingSquareIllusion | title=Rotating Square Illusion}}): Rotating Square Illusion
- Rotation ({{MathWorld | urlname=Rotation | title=Rotation}}): Rotation
- Rotation Formula ({{MathWorld | urlname=RotationFormula | title=Rotation Formula}}): Rotation Formula
- Rotation Group ({{MathWorld | urlname=RotationGroup | title=Rotation Group}}): Rotation Group
- Rotation Matrix ({{MathWorld | urlname=RotationMatrix | title=Rotation Matrix}}): Rotation Matrix
- Rotation Number ({{MathWorld | urlname=RotationNumber | title=Rotation Number}}): Rotation Number
- Rotation Operator ({{MathWorld | urlname=RotationOperator | title=Rotation Operator}}): Rotation Operator
- Roth's Removal Rule ({{MathWorld | urlname=RothsRemovalRule | title=Roth's Removal Rule}}): Roth's Removal Rule
- Roth's Theorem ({{MathWorld | urlname=RothsTheorem | title=Roth's Theorem}}): Roth's Theorem
- Rotkiewicz Theorem ({{MathWorld | urlname=RotkiewiczTheorem | title=Rotkiewicz Theorem}}): Rotkiewicz Theorem
- Rotoinversion ({{MathWorld | urlname=Rotoinversion | title=Rotoinversion}}): Rotoinversion
- Rotor ({{MathWorld | urlname=Rotor | title=Rotor}}): Rotor
- Rotunda ({{MathWorld | urlname=Rotunda | title=Rotunda}}): Rotunda
- Rouché's Theorem ({{MathWorld | urlname=RouchesTheorem | title=Rouché's Theorem}}): Rouché's Theorem
- Rough Number ({{MathWorld | urlname=RoughNumber | title=Rough Number}}): Rough Number
- Roulette ({{MathWorld | urlname=Roulette | title=Roulette}}): Roulette
- Round ({{MathWorld | urlname=Round | title=Round}}): Round
- Rounded Rectangle ({{MathWorld | urlname=RoundedRectangle | title=Rounded Rectangle}}): Rounded Rectangle
- Rounding ({{MathWorld | urlname=Rounding | title=Rounding}}): Rounding
- Rounding Error ({{MathWorld | urlname=RoundingError | title=Rounding Error}}): Rounding Error
- Roundness ({{MathWorld | urlname=Roundness | title=Roundness}}): Roundness
- Round Number ({{MathWorld | urlname=RoundNumber | title=Round Number}}): Round Number
- Roundoff Error ({{MathWorld | urlname=RoundoffError | title=Roundoff Error}}): Roundoff Error
- Round Robin Tournament ({{MathWorld | urlname=RoundRobinTournament | title=Round Robin Tournament}}): Round Robin Tournament
- Route ({{MathWorld | urlname=Route | title=Route}}): Route
- Routh-Hurwitz Theorem ({{MathWorld | urlname=Routh-HurwitzTheorem | title=Routh-Hurwitz Theorem}}): Routh-Hurwitz Theorem
- Routh's Theorem ({{MathWorld | urlname=RouthsTheorem | title=Routh's Theorem}}): Routh's Theorem
- Row-Convex Polyomino ({{MathWorld | urlname=Row-ConvexPolyomino | title=Row-Convex Polyomino}}): Row-Convex Polyomino
- Row Echelon Form ({{MathWorld | urlname=RowEchelonForm | title=Row Echelon Form}}): Row Echelon Form
- RowReduce ({{MathWorld | urlname=RowReduce | title=RowReduce}}): RowReduce
- Row-Reduced Echelon Form ({{MathWorld | urlname=Row-ReducedEchelonForm | title=Row-Reduced Echelon Form}}): Row-Reduced Echelon Form
- Row Space ({{MathWorld | urlname=RowSpace | title=Row Space}}): Row Space
- Row Vector ({{MathWorld | urlname=RowVector | title=Row Vector}}): Row Vector
- Roy-Floyd Algorithm ({{MathWorld | urlname=Roy-FloydAlgorithm | title=Roy-Floyd Algorithm}}): Roy-Floyd Algorithm
- Royle Graphs ({{MathWorld | urlname=RoyleGraphs | title=Royle Graphs}}): Royle Graphs
- Roy-Warshall Algorithm ({{MathWorld | urlname=Roy-WarshallAlgorithm | title=Roy-Warshall Algorithm}}): Roy-Warshall Algorithm
- R+ ({{MathWorld | urlname=R-Plus | title=R+}}): R+
- RPN ({{MathWorld | urlname=RPN | title=RPN}}): RPN
- RSA Encryption ({{MathWorld | urlname=RSAEncryption | title=RSA Encryption}}): RSA Encryption
- RSA Number ({{MathWorld | urlname=RSANumber | title=RSA Number}}): RSA Number
- RSolve ({{MathWorld | urlname=RSolve | title=RSolve}}): RSolve
- R* ({{MathWorld | urlname=R-Star | title=R*}}): R*
- Rubber-Sheet Geometry ({{MathWorld | urlname=Rubber-SheetGeometry | title=Rubber-Sheet Geometry}}): Rubber-Sheet Geometry
- Rubik's Clock ({{MathWorld | urlname=RubiksClock | title=Rubik's Clock}}): Rubik's Clock
- Rubik's Cube ({{MathWorld | urlname=RubiksCube | title=Rubik's Cube}}): Rubik's Cube
- Rudin-Shapiro Sequence ({{MathWorld | urlname=Rudin-ShapiroSequence | title=Rudin-Shapiro Sequence}}): Rudin-Shapiro Sequence
- Rudvalis Group ({{MathWorld | urlname=RudvalisGroup | title=Rudvalis Group}}): Rudvalis Group
- Ruffini-Horner Method ({{MathWorld | urlname=Ruffini-HornerMethod | title=Ruffini-Horner Method}}): Ruffini-Horner Method
- Rule ({{MathWorld | urlname=Rule | title=Rule}}): Rule
- Rule 102 ({{MathWorld | urlname=Rule102 | title=Rule 102}}): Rule 102
- Rule 110 ({{MathWorld | urlname=Rule110 | title=Rule 110}}): Rule 110
- Rule 126 ({{MathWorld | urlname=Rule126 | title=Rule 126}}): Rule 126
- Rule 150 ({{MathWorld | urlname=Rule150 | title=Rule 150}}): Rule 150
- Rule 158 ({{MathWorld | urlname=Rule158 | title=Rule 158}}): Rule 158
- Rule 182 ({{MathWorld | urlname=Rule182 | title=Rule 182}}): Rule 182
- Rule 188 ({{MathWorld | urlname=Rule188 | title=Rule 188}}): Rule 188
- Rule 190 ({{MathWorld | urlname=Rule190 | title=Rule 190}}): Rule 190
- Rule 220 ({{MathWorld | urlname=Rule220 | title=Rule 220}}): Rule 220
- Rule 222 ({{MathWorld | urlname=Rule222 | title=Rule 222}}): Rule 222
- Rule 250 ({{MathWorld | urlname=Rule250 | title=Rule 250}}): Rule 250
- Rule 28 ({{MathWorld | urlname=Rule28 | title=Rule 28}}): Rule 28
- Rule 30 ({{MathWorld | urlname=Rule30 | title=Rule 30}}): Rule 30
- Rule 50 ({{MathWorld | urlname=Rule50 | title=Rule 50}}): Rule 50
- Rule 54 ({{MathWorld | urlname=Rule54 | title=Rule 54}}): Rule 54
- Rule 60 ({{MathWorld | urlname=Rule60 | title=Rule 60}}): Rule 60
- Rule 62 ({{MathWorld | urlname=Rule62 | title=Rule 62}}): Rule 62
- Rule 90 ({{MathWorld | urlname=Rule90 | title=Rule 90}}): Rule 90
- Rule 94 ({{MathWorld | urlname=Rule94 | title=Rule 94}}): Rule 94
- Ruled Surface ({{MathWorld | urlname=RuledSurface | title=Ruled Surface}}): Ruled Surface
- Ruled Surface Directrix ({{MathWorld | urlname=RuledSurfaceDirectrix | title=Ruled Surface Directrix}}): Ruled Surface Directrix
- Rule of 72 ({{MathWorld | urlname=Ruleof72 | title=Rule of 72}}): Rule of 72
- Rule of Inference ({{MathWorld | urlname=RuleofInference | title=Rule of Inference}}): Rule of Inference
- Rule of Nines ({{MathWorld | urlname=RuleofNines | title=Rule of Nines}}): Rule of Nines
- Rule of Signs ({{MathWorld | urlname=RuleofSigns | title=Rule of Signs}}): Rule of Signs
- Ruler ({{MathWorld | urlname=Ruler | title=Ruler}}): Ruler
- Ruler Function ({{MathWorld | urlname=RulerFunction | title=Ruler Function}}): Ruler Function
- Ruling ({{MathWorld | urlname=Ruling | title=Ruling}}): Ruling
- Rumors ({{MathWorld | urlname=Rumors | title=Rumors}}): Rumors
- Rumor Spreading ({{MathWorld | urlname=RumorSpreading | title=Rumor Spreading}}): Rumor Spreading
- Run ({{MathWorld | urlname=Run | title=Run}}): Run
- Runge-Kutta Method ({{MathWorld | urlname=Runge-KuttaMethod | title=Runge-Kutta Method}}): Runge-Kutta Method
- Runge's Theorem ({{MathWorld | urlname=RungesTheorem | title=Runge's Theorem}}): Runge's Theorem
- Runge-Walsh Theorem ({{MathWorld | urlname=Runge-WalshTheorem | title=Runge-Walsh Theorem}}): Runge-Walsh Theorem
- Run-Length Encoding ({{MathWorld | urlname=Run-LengthEncoding | title=Run-Length Encoding}}): Run-Length Encoding
- Running Average ({{MathWorld | urlname=RunningAverage | title=Running Average}}): Running Average
- Running Knot ({{MathWorld | urlname=RunningKnot | title=Running Knot}}): Running Knot
- Running Maximum ({{MathWorld | urlname=RunningMaximum | title=Running Maximum}}): Running Maximum
- Running Sum ({{MathWorld | urlname=RunningSum | title=Running Sum}}): Running Sum
- Running Time ({{MathWorld | urlname=RunningTime | title=Running Time}}): Running Time
- Russell's Antinomy ({{MathWorld | urlname=RussellsAntinomy | title=Russell's Antinomy}}): Russell's Antinomy
- Russell's Paradox ({{MathWorld | urlname=RussellsParadox | title=Russell's Paradox}}): Russell's Paradox
- Russian Doll Prime ({{MathWorld | urlname=RussianDollPrime | title=Russian Doll Prime}}): Russian Doll Prime
- Russian Multiplication ({{MathWorld | urlname=RussianMultiplication | title=Russian Multiplication}}): Russian Multiplication
- Russian Roulette ({{MathWorld | urlname=RussianRoulette | title=Russian Roulette}}): Russian Roulette
- Ruth-Aaron Pair ({{MathWorld | urlname=Ruth-AaronPair | title=Ruth-Aaron Pair}}): Ruth-Aaron Pair
- Rutishauser's Rule ({{MathWorld | urlname=RutishausersRule | title=Rutishauser's Rule}}): Rutishauser's Rule
- Ryser Formula ({{MathWorld | urlname=RyserFormula | title=Ryser Formula}}): Ryser Formula