Question

cos 8П/15× cos П/5 +sin 8П/15×sinП/5​

Answer 1

Ответ:$frac{1}{2}$

Объяснение:

cos(t)*cos(s)+sin(t)*sin(s)= cos(t-s)

$cos(frac{8pi }{15}-frac{pi }{5} )=cos(frac{pi }{3})\ cos(frac{pi }{3} )=frac{1}{2}$