Solving the Equation of cos^3(e^4(theta))

[delfam]

Homework Statement

(cos^3)(e^4(theta))

Homework Equations

f(x)=f(g(x))

The Attempt at a Solution

u=e^49theta))

-3sin^2(e^4(theta)) x e^4(theta)


Just not sure what I'm doing wrong, I know what the answer is I'm just not sure how to get to it.

 

[Raskolnikov]

For starters, you need to be clearer. Is your problem $$cos(e^4\theta)^3$$ ? It's hard to tell from the way you wrote it. If it is, then you need to use the chain rule, which is:

$$[f( g(x) )] ' = f'(g(x)) * g'(x).$$

 

[Raskolnikov]

The typical way to recall the steps if you're having trouble is:

1. derivative of the outside function, leaving the inside function untouched.
2. multiply by the derivative of the inside function.

 

[delfam]

the question is cos^3 * e^4theta the theta is connected to the raised power of 4.

 

[Raskolnikov]

You really need to use LaTeX or appropriately placed parentheses. My comments on the chain rule still apply. Where exactly are you getting stuck?