y=a(x-h)2+k (a 0) The turning point is (h,k). Factor out a from the quadratic and linear terms before completing the square. **Sign of a** | **Turning point** | **Sketch** a>0 | Minimum point (h,k) minimum value y=k | a<0 | Maximum point (h,k) maximum value y=k |

The turning point is \((h,k)\). Factor out \(a\) from the quadratic and linear terms before completing the square.

Minimum point \((h,k)\)
minimum value \(y=k\)

Maximum point \((h,k)\)
maximum value \(y=k\)

Maximum and Minimum Values by Completing the Square

Maximum and Minimum Values by Completing the Square