What is the derivative of sin(2x)?

2 Answers
Jan 25, 2015

2*cos(2x)

I would use the Chain Rule:

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First derive sin and then the argument 2x to get:
cos(2x)*2

Jun 20, 2018

2cos2x

Explanation:

The key realization is that we have a composite function, which can be differentiated with the help of the Chain Rule

f'(g(x))*g'(x)

We essentially have a composite function

f(g(x)) where

f(x)=sinx=>f'(x)=cosx and g(x)=2x=>g'(x)=2

We know all of the values we need to plug in, so let's do that. We get

cos(2x)*2

=>2cos2x

Hope this helps!