Question

Срочно, Тригонометрия, 10 кд​

Answer 1

$cos^2 \frac{\pi}{8}+sin \frac{\pi}{8} \cdot cos \frac{3\pi}{8} =$

$cos^2 \frac{\pi}{8}+sin \frac{\pi}{8} \cdot cos\left( \frac{\pi}{2}- \frac{\pi}{8} \right) =$

$cos^2 \frac{\pi}{8}+sin \frac{\pi}{8} \cdot sin \frac{\pi}{8} \right) =$

$cos^2 \frac{\pi}{8}+sin^2 \frac{\pi}{8}=1$

Ответ: 1