Differentiation formula for Cos 2x=?

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Answer 1 · 2018-03-09T17:29:40

$=>d/dx(Cos2x)=-2sin2x$

We have:

$d/dx(Cos2x)$

Two rules to remember here:

$d/dx(cosx)=-sinx$

$d/dx(g(h(x)))=g'(h(x))*h'(x)$

$d/dx(x^n)=nx^(n-1)$ where $n$ is a constant.

Therefore:

$d/dx(Cos2x)=-sin2x*d/dx(2x)$

$=>d/dx(Cos2x)=-sin2x*2$

$=>d/dx(Cos2x)=-2sin2x$