CAlculus Help!
find the derivative of the function.
g(x)=3arccos(x/2)

Question

CAlculus Help!
find the derivative of the function.
g(x)=3arccos(x/2)

anonymous · Answer

are u familiar with the derivative of $$\cos^{-1}$$

anonymous · Answer

yes

anonymous · Answer

$$g(x)=3cos^{-1}(\frac{x}{2})$$
$$cos(\frac{g(x)}{3})=cos(cos^{-1}(\frac{x}{2})=\frac{x}{2}$$
if you take the derivative of that, you can find your answer much easier using chain rule without having to memorize arccos derviatives.

anonymous · Answer

$$g'(x) = 3[-\frac{1/2}{\sqrt{1-(\frac{1}{2})^{2}}}]$$
that took a while, but this is how i'm learning to do these derivatives

anonymous · Answer

but i HAVE to memorize the arccos derivatives!

anonymous · Answer

umm okay can u exaplin step by step? pleas?

anonymous · Answer

2le or me?

anonymous · Answer

i mean explain?

anonymous · Answer

well you take the derivative and plug in the the values to the formula.

anonymous · Answer

why did u take out the 3?

anonymous · Answer

the (3) is the constant multiple rule

anonymous · Answer

its a constant being multiplied so its carried out

anonymous · Answer

o okay. :]

anonymous · Answer

wait and the 1/2? y is it on top?

anonymous · Answer

so why is the 1/2 on top again?

zepdrix · Answer

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