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) and = nx^{n - 1}

Let us take y = cos x³

So, by using the above formula, we have

cos x³ = - sin(x³)(x³) = - 3x² sin(x³)

Differentiation of y = cos x³ is - 3x² sin(x³)