Improvement of Descartes’ rule of signs. (Perfectionnement de la règle des signes de Descartes.) (French) Zbl 1519.26006
Two classical results on the number of positive roots of a polynomial is Descartes’ rule of signs and Sturm’s theorem. These results are complemented by E. N. Laguerre’s theorem [Resal J. (3) 9, 99–147 (1883; JFM 15.0063.02)].
Reviewer: Franz Lemmermeyer (Jagstzell)
MSC:
26C10 | Real polynomials: location of zeros |
12D10 | Polynomials in real and complex fields: location of zeros (algebraic theorems) |