To Find: Differentiation

NOTE : When 2 functions are in the product then we used product rule i.e

Formula used: (cos nu) = - sin (nu)(nu).

Let us take y = cos5x.

So, by using the above formula, we have

(cos5x) = - sin(5x) (5x) = - 5sin5x.

Differentiation of y = cos 5x is - 5sin5x