CPM Homework Help : AC Problem 4-135

For each quadratic function below, use the idea of completing the square to write it in graphing form. Then state the vertex of each parabola. Homework Help ✎

$f(x)=x^2+6x+15$
Step 1(a):
Set up tiles to reflect the problem.
Step 2(a):
Write an equivalent equation using the tile arrangement.
Answer (a):
$f(x)=(x+3)^2+6$ , vertex at $(−3, 6)$

$y=x^2−4x+9$
Hint (b):
Refer to part (a.)

$f(x)=x^2+8x$
Hint (c):
You will need to add and subtract the same number of tiles on the right side of the equation in order to complete a square.

$y=x^2+5x−2$
Hint (d):
You will need to add and subtract the same number of tiles on the right side of the equation in order to complete a square.

Use the eTool below to help complete these problems.
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