# Math Help - Relative Maximum/minimum help!

1. ## Relative Maximum/minimum help!

I know how to do A and B but can some one help me on C please.

2. Originally Posted by lilwayne
I know how to do A and B but can some one help me on C please.
what do the first and second derivative tests for extrema tell you?

3. Solve $f'(x) = 0, g'(x)=0, h'(x)=0$

4. Originally Posted by lilwayne
I know how to do A and B but can some one help me on C please.
Dear lilwayne,

Take the first derivative of f(x) and consider its behavior in the regions x<0 and x>0.

If $\frac{df(x)}{dx}<0~ when ~x<0 ~and ~\frac{df(x)}{dx}>0~ when~ x>0$ then there is a relative minimum at x=0.

If $\frac{df(x)}{dx}>0 ~when~ x<0 ~and~ \frac{df(x)}{dx}<0 ~when ~x>0$ then there is a relative maximum at x=0.

If the derivative is positive or negative in both regions then x=0 is neither a ralative maximum nor a relative minimum.

Hope you understood.

5. Thanks a lot!