# What is the derivative of cos x^5?

$\cos {x}^{5}$ is $- \sin {x}^{5} \cdot 5 {x}^{4}$
the derrivative of $\cos {x}^{5}$ is $- \sin {x}^{5} \cdot 5 \cdot {x}^{4}$ which is found by
derrivative of $f \left(g \left(x\right)\right) = f ' \left(g \left(x\right)\right) \cdot g ' \left(x\right)$