math
posted by nicko on .
If g is a differentiable function such that g(x) < 0 for all real numbers x and if f'(x)=(x24)g(x), which of the following is true?

The answer is "B", f(x) has a minimum at x=2 and a maximum at x=+2.
For explanations, see
http://www.jiskha.com/display.cgi?id=1293845056