A trinomial is which of the following?

• A. Polynomial with three terms
• B. Polynomial with two terms
• C. Monomial
• D. Four terms

Answer: (A)

A trinomial is a polynomial with three terms. A polynomial is the sum or difference of monomials, and the number of terms you see tells you what kind of polynomial it is. If you have three addends like x^2 + 3x + 5, there are three terms, so it’s a trinomial. If there’s only one term, like 7x^2, that’s a monomial. If there are two terms, like x^2 + 4, that’s a binomial. Four terms would be a four-term polynomial (sometimes called a quadrinomial).