5.1.4 Completing the Square (continued)
Example 2 Completing the Square Recall that a perfect-square trinomial can be factored into the square of a binomial. A perfect-square trinomial has the form a 2 − 2 ab + b 2 = ( a − b ) 2 or a 2 + 2 ab + b 2 = ( a + b ) 2 . To write a quadratic expression of the form x 2 + bx as a perfect square trinomial, add ( b /2) 2 , which is called completing the square.
233
Made with FlippingBook flipbook maker