# Math Help - Condition for increasing function

1. ## Condition for increasing function

The largest interval on which the function f(x) = x2 + 4x + 2 is increasing is

a. [0, ~)
b. (-~, 0]
c. [-2, ~)
d. (-~, -2]
e. (-2, ~)

The condition that the function is increasing is f '(x) > 0 or f ' (x) $\geq$ 0?

Thanks

2. if f ' (x) 0, at the x value where f'(x)=0, the function is not increasing, as the slope is 0.
Therefore, i think there should not be the equal sign