Derivatives are defined as the rate of change of any function f(x) with respect to an independent variable.
Answer: The Derivative of y = cos 2x is − 2 sin 2 x
Let us proceed for this problem step by step
On differentiating cos x, we get - sin x. [d/dx cosx = - sin x]
Since cos 2x is a composition of two functions which are cosine function and 2x.
On differentiating 2x, we get 2. [d/dx 2x =2]
So, using chain rule, we have
d y/ d x = − 2 sin 2x