# Math Help - Solving for x

1. ## Solving for x

I'm trying to find out the concavity of

I know the derivative is $(2/3)x^-(2/3)$ but I do not know how to solve for X

Thanks

2. Originally Posted by Chrisss
I'm trying to find out the concavity of

I know the derivative is $(2/3)x^-(2/3)$ but I do not know how to solve for X

Thanks

Solve WHAT for x?? You need the second derivative and check where it is positive and where negative. That'll give you the concavity of the function.

Tonio