## Alexalayne Group Title What is the f'(x) of f(X)=sin^3x one year ago one year ago

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1. LogicalApple Group Title

Have you attempted this one yet ?

2. Alexalayne Group Title

yeah

3. LogicalApple Group Title

$f(x) = \sin ^{3}(x)$ Did I write this down correctly? If so, try substitution. For example, let u = sin(x) and then take the derivative of u^3

4. Alexalayne Group Title

I got f'(X) is 9x^2cosx^2

5. Alexalayne Group Title

that is 3u^2

6. LogicalApple Group Title

3u^2 du/dx, yes. Now what is du/dx if u = sin x?

7. LogicalApple Group Title

In other words, what is u' if u = sin x

8. Alexalayne Group Title

cosx^2

9. LogicalApple Group Title

What is the derivative of sin(x) ?

10. Alexalayne Group Title

COS

11. LogicalApple Group Title

Great, so du/dx = cos x So we have 3u^2 * cos x Substitute u = sin(x) back in and what do we end up with ?

12. LogicalApple Group Title

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