# Math Help - derivative problem

1. ## derivative problem

Given f(x) = (x^3-2x)/sqrt(2x+1) find f'(x)

I can do the first step but then I'm stuck.. Can't wait to fail my test friday.

2. Originally Posted by tbenne3
Given f(x) = (x^3-2x)/sqrt(2x+1) find f'(x)

I can do the first step but then I'm stuck.. Can't wait to fail my test friday.
Is this a multi-stepped problem?

3. Originally Posted by Drexel28
Is this a multi-stepped problem?
Don't know.. If I give you the answer could you figure it out?

4. Just use the quotient rule, taking the chain rule into consideration. Are you still stuck after that? I'm not sure what 'step' you're on in your solution. ^^

5. Originally Posted by experiment00005
Just use the quotient rule, taking the chain rule into consideration. Are you still stuck after that? I'm not sure what 'step' you're on in your solution. ^^
Hmm.. I thought all I would need to do is the quotient rule.. Why does the chain rule need to be applied to?

6. The square root: $\sqrt{f(x)}= (f(x))^{1/2}$ so, by the chain rule, its derivative is $(1/2)(f(x))^{-1/2}f'(x)$.

7. Originally Posted by tbenne3
Given f(x) = (x^3-2x)/sqrt(2x+1) find f'(x)

I can do the first step but then I'm stuck.. Can't wait to fail my test friday.