## zarkam21 one year ago Help, will medal =)

1. zarkam21

2. anonymous

To solve this, recall the definition of a perfect square trinomial.

3. anonymous

A perfect square trinomial means that the factorized form of the trinomial takes on the form of $(x-a)^2$

4. anonymous

This means that the roots of the quadratic equation must be repeated.

5. anonymous

Now, you just need to plug the coefficients of the given trinomial into the quadratic formula.

6. anonymous

$x = \frac{-b \pm \sqrt{ b^2-4ac }}{ 2a }$

7. anonymous

Notice however, that you have this plus or minus operation in the quadratic formula.

8. anonymous

That plus or minus operation is what normally gives you two distinct roots. But you want a repeated root. Your solution is to set the square root term to 0.

9. zarkam21

10. anonymous

No, by setting the square root term to 0, I mean:$b^2-4ac = 0$

11. anonymous

From the problem a = 1, b = -28, c = ?

12. anonymous

We are trying to solve for variable c.$(-28)^2 = 4c$

13. anonymous

Do you understand?

14. zarkam21

yes so I would just divide (-28)^2 by 4

15. anonymous

Correct, and that would be the constant term for your perfect square trinomial

16. zarkam21

196?

17. zarkam21

Is 196 correct

18. anonymous

Correct