Question

calcule: S = cos0 + cos 2 pi/3 + cos 4 pi/ 3 + cos 2pi

Answer 1

Vamos la

cos(0) = 1

cos(2pi/3) = -1/2

cos(4pi/3) = -1/2

cos(2pi) = 1

S = 1 - 1/2 - 1/2 + 1 = 1