Question

what's the derivative of cosxsinx

Answer 1

use the product rule

Answer 2

product rule
\[(fg)'=f'g+g'f\] use
\[f(x)=\sin(x), f'(x)=\cos(x), g(x)=\cos(x), g'(x)=-\sin(x)\]

Answer 3

f(x)=cos x
g(x)=sin x

product rule:
d/dx ( f(x)g(x) ) = f'(x)g(x) + f(x) g'(x)

Answer 4

dy/dx of cosxsinx = (-sinx)(sinx) + cosxcosx = cos^2x - sin^2x = ??

Answer 5

yupp thats right....and cos^2x-sin^2x = cos(2x)

Answer 6

= (1+cos2x)/2 - (1-cos2x)/2 = 2(cos2x)2 = yeaaaaeee!

Answer 7

hehe