# Evaluate the indefinite integral. {eq}\int {{{\cos }^8}\left( \theta \right)\sin \left( \theta \right)} \ d\theta {/eq}

## Question:

Evaluate the indefinite integral.

{eq}\int {{{\cos }^8}\left( \theta \right)\sin \left( \theta \right)} \ d\theta {/eq}

## U-Substitution Method:

In calculus integral, the u-substitution method to solve complicated integral problems (both definite and indefinite integrals). Here, we convert the integral into a normal integral problem (which is easy to solve) by using the substitution method. It means we substitute {eq}u {/eq} instead of a part of the integrand, and we also change the differential value of the integral in terms of the new variable. It is also known by different names such as integration by substitution, the reverse chain rule, and change of variables.