(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find the max/min of the function for [0,pi/2]

f(x)= kcos^{2}xsin(x)

2. Relevant equations

Product Rule and chain rule

3. The attempt at a solution

f^{'}(x)= k(2cosx(-sinx)(sinx)+cos^{2}xcosx)

f^{'}(x)= kcosx(-2sin^{2}x+cos^{2}x)

Set eqaution to 0

(2sin^{2}x+cos(x)^{2}) = 0

2(1-cos^{2}x)+cos(x)^{2}= 0

cos^{2}x = 2

?

Now I'm stuck. There should be a max or min.

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# Homework Help: Derivative with Constant

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