Question

Over which interval is the graph of f(x) = 1/2 x2 + 5x + 6 increasing?

A) (–6.5, ∞)
B) (–5, ∞)
C) (–∞, –5)
D) (–∞, –6.5)

Answer 1

yeah the answer is indeed B

Answer 2

If you look at the graph of f(x) = 1/2 x2 + 5x + 6, you can see that it is increasing at interval (-5, ∞).

So the answer would be B.