A polynomial with three terms.
Trinomial
See also
Binomial, Monomial, Polynomial, Trinomial Coefficient, Trinomial Identity, Trinomial TriangleExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Trinomial." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Trinomial.html