# F(x) = e^(2x) and g(x) = lnx. what is the derivative of f(g(x)) at x=e

1. Feb 3, 2009

### meredith

1. The problem statement, all variables and given/known data
f(x) = e^(2x) and g(x) = lnx. what is the derivative of f(g(x)) at x=e

2. Relevant equations
dy/dx = f'g(x) x g'(x)

3. The attempt at a solution
i cant figure it out!

2. Feb 3, 2009

### Dick

Try it! What's f'(x)? g'(x)? f'(g(x))?

3. Feb 3, 2009

### v0id19

remember your chain rule:
$$[f(g(x))]'=f'(g(x))\cdot g'(x)$$
take each derivative separately and put it all together if it seems too complicated, that helps me a lot

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