# Thread: Critical Point / Derivative Test!!!! HELP

1. ## Critical Point / Derivative Test!!!! HELP

Help me solve this problem....

2. ## Re: Critical Point / Derivative Test!!!! HELP

do you know how to find critical points? I'm guessing you should.

3. ## Re: Critical Point / Derivative Test!!!! HELP

I taught i did ...but i keep getting the wrong answer....i just need a fresh new set of set....im taking an online class it and it explains less

4. ## Re: Critical Point / Derivative Test!!!! HELP

Originally Posted by yeatch
I taught i did ...but i keep getting the wrong answer....i just need a fresh new set of set....im taking an online class it and it explains less
solve $\dfrac {df}{dx}(x)=0$ for $x$ to find your critical points.

5. ## Re: Critical Point / Derivative Test!!!! HELP

After i find the critical point of the derivative, whats next??

6. ## Re: Critical Point / Derivative Test!!!! HELP

Originally Posted by yeatch
After i find the critical point of the derivative, whats next??
$\dfrac {d^2f}{{dx}^2}(x_{crit})>0 \Rightarrow x_{crit} \mbox{ is a local minimum. }$

$\dfrac {d^2f}{{dx}^2}(x_{crit})<0 \Rightarrow x_{crit} \mbox{ is a local maximum. }$