Question

What is the vertex of the graph of the function below?

Answer 1

Answer:

D. (4, -4)

Step-by-step explanation:

Convert to vertex form by completing the square.

For a polynomial y = x² + bx + c, first add and subtract (b/2)² to the polynomial.  Then factor.

Here, b = -8.  So (b/2)² = (-8/2)² = 16.

y = x² − 8x + 12

y = x²− 8x + 16 − 16 + 12

y = (x − 4)² − 16 + 12

y = (x − 4)² − 4

The vertex is (4, -4).