Question

What is a polynomial with 4 terms?

Answer 1

You can say that it's a quadrinomial, but that just means it has `4` terms.

If those terms are in a single variable of highest degree `3`, then it's called a cubic.

Explanation:

`ax^3+bx^2+cx+d` is a quadrinomial and a cubic.

`ax^5+bx^2+cx+d` is quadrinomial but a quintic (the term of highest degree has degree `5`).

`ax^3+cx+d` is a cubic but not a quadrinomial.

`ax^3+bx^2+cx+d/x` is a quadrinomial but not a polynomial.