Perfect+Square+Trinomials

=__Perfect Square Trinomials__=

To identify a Perfect Square Trinomial:

 * The first and last terms are ** //positive.// **
 * The middle term is //**2 times the product**// of the outer terms.

Example: 4x 2 + 36x + 81

1. Take the ** square root ** of the ** two outer terms **.  Square root of 4x 2 =  ** 2x ** Square root of 81 = **9**

2. Multiple these **terms** together, then ** multiple by 2 **

(2x * 9) = 18x (* 2) =   **  36x [This should equal the middle term from your original equation] **

3a. Since the middle term is ** positive **, the ** sign **in your equation will be ** positive ** as well.

4x 2 ** + ** 36x + 81 = (2x ** + ** 9) 2

3b. //__If the middle term is **negative** ,__// then your ** sign **would be **negative**, too.

4x 2 ** - ** 36x + 81 = (2x ** - ** 9) 2



Here's another example: 4x 2 + 12x + 9

Square root of 4x 2 = ** 2x ** Square root of 9 = ** 3 **  (2x * 3) = 6x **(* 2) ** = 12x

(Since your sign is positive...)