## anonymous 3 years ago Find local min and max and the points of inflection for f(x)= 3(cos(x))^2 - 6sin(x)

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1. anonymous

Do you know how to do the chain rule with respect to trig functions?

2. anonymous

Example $\bigg(\cos^4(x)\bigg)^{\prime}=4\cos^3(x)$

3. anonymous

oh and generally $\cos^2(x) = (\cos(x))^2$

4. anonymous

?

5. anonymous

let me write it correctly $f'(x)=-6\cos(x)\sin(x)-6\cos(x)]$ that's better

6. myininaya

$\(cos^2(x))'=2\cos(x)(-\sin(x))=-2\cos(x)\sin(x)$

7. myininaya

@freewilly922 your example is a little off

8. anonymous

mine was way off!

9. myininaya

Corrected example from above: $(\cos^4(x))'=4\cos^3(x)(-\sin(x))=-4\cos^3(x)\sin(x)$

10. anonymous

i just ate a mini kitkat