| binomial | A polynomial with exactly two terms, such as 5y2 – 4x and x5 + 6. |
| perfect square | A square of a whole number. Since 12 = 1, 22 = 4, 32 = 9, etc., 1, 4, and 9 are perfect squares. |
| perfect square trinomial | A trinomial that is the product of a binomial times itself, such as a2 + 2ab + b2 (from (a + b)2), and a2 – 2ab + b2 (from (a – b)2). |
| trinomial | A polynomial with exactly three terms, such as 5y2 – 4y + 4 and x2 + 2xy +y2. |