Answer
$-\frac{3}{8}\pi$
Work Step by Step
Use the propriety of definite integrals:
$$\int_a^b f(x)=-\int_b^a f(x)$$
$$\int_{\pi}^{0}\sin^{4}(\theta)d\theta=\int_{\pi}^{0}\sin^{4}(x)dx=-\int_{0}^{\pi}\sin^{4}(x)dx=-\frac{3}{8}\pi$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.