Question

At what value of x does the minimum or maximum occur for the function below? f(x) = 8(x + 8)2 + 9 A. maximum at x = 9 B. minimum at x = 9 C. maximum at x = -8 D. minimum at x = -8

Answer 1

$8 {(x + 8)}^{2} + 9 \geqslant 9 \: ( {(x + 8)}^{2} \geqslant 0) \\ \Leftrightarrow x + 8 = 0\Leftrightarrow x = - 8 \\ \Rightarrow D.\: Minimum\: at\: x=-8$