SOLUTION: Use the Completing the Square method to find the vertex form of the quadratic function y = x^2 + 7x + 12.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: Use the Completing the Square method to find the vertex form of the quadratic function y = x^2 + 7x + 12.       Log On


   

Question 189971: Use the Completing the Square method to find the vertex form of the quadratic function y = x^2 + 7x + 12.
Found 2 solutions by Mathtut, nerdybill:
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
y=%28x%5E2%2B7x%2B%2849%2F4%29%29-49%2F4%2B12
:
y=%28x%2B7%2F2%29%5E2-1%2F4
:
vertex is at (-7/2,-1/4)

Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
Vertex form is:
y= a(x-h)^2+k
.
y = x^2 + 7x + 12
y = (x^2 + 7x + __ ) + 12 - __
.
Fill the blank with 1/2 of 'b' coefficient squared:
((1/2)(7))^2 = (7/2)^2 = 49/4
.
y = (x^2 + 7x + 49/4 ) + 12 - 49/4
y = (x^2 + 7x + 49/4 ) + 48/4 - 49/4
y = (x^2 + 7x + 49/4 ) - 1/4
y = (x + 7/2)^2 - 1/4 (this is what they're looking for)