Question

Помогите решить
√8-√32sin²$\frac{11\pi}{8}$

Answer 1

$2 \sqrt{2}-4 \sqrt{2} *sin^2 \frac{11 \pi }{8}=2 \sqrt{2} (1-2sin^2 \frac{11 \pi }{8}) \\ 1-2sin^2 \alpha =cos2 \alpha \\ 2 \sqrt{2} * cos \frac{11 \pi }{4}=2 \sqrt{2} * (- \frac{ \sqrt{2} }{2} )=-2$