Question

Обчислити
cos(-35pi/3)

Answer 1

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