What is the derivative of f(x)=2cosx-cos2xdxf(x)=2cosx−cos2xdx?

1 Answer
De Rono
Oct 29, 2015

-2sin x+2sin 2x−2sinx+2sin2x

Explanation:

Note that

d/(dx)(2cos x - cos 2x)= 2d/(dx)(cosx )-d/(dx)(cos 2x)ddx(2cosx−cos2x)=2ddx(cosx)−ddx(cos2x)
=-2sin x+2sin 2x=−2sinx+2sin2x

Since d/(dx)(cos x) = -sin xddx(cosx)=−sinx and d/(dx)(cos2x)= -2sin2xddx(cos2x)=−2sin2x.

Related questions
Impact of this question
1017 views around the world
You can reuse this answer
Creative Commons License