biquadratic

From bi- +‎ quadratic.

biquadratic (not comparable)

1. (mathematics) Of a polynomial expression, involving only the zeroth, second, and fourth powers of a variable, as x⁴ + 3x² + 2. Sometimes extended to any expression involving the biquadrate or fourth power (but no higher powers), as x⁴ − 4x³ + 3x² − x + 1.

biquadratic (plural biquadratics)

1. (mathematics) A biquadratic equation.

• quadratic
• quartic