Question

Вычислите;cos(-35п/3)

Answer 1

$cos(- frac{35 pi }{3})=cos frac{35 pi }{3}=cos( frac{36 pi }{3}- frac{ pi }{3})=cos(12 pi - frac{ pi }{3})= \ \ =cos(- frac{ pi }{3})=cos( frac{ pi }{3})= frac{1 }{2}$