Question

Complete the square to determine the minimum or maximum value of the function defined by the expression.

−x2 − 4x + 15

Answer 1

Max, 19
You know that it will have a minimum when the x^2 is positive, and a maximum when it’s negative. You can remember that when you’re thinking positively, you’re smiling (minimum). When you think negative, you’re frowning (maximum)
Hope this helps :)