| completing the square | A method for solving quadratic equations by rewriting one side of the equation as a squared binomial. |
| 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). |
| square root property | If x2 = a2, then x = a or x = −a. |