Решить уравнение( 0,5cosпt)^2=0,125

0.25 cos^2 (pit)=0.125

cos^2(pit) =0.25

cos(pit) =0.5                                          cos(pit) =-0.5

pit = +-pi/3 +2pin                                   pit = -+2pi/3+2pin

t = +-1/3 =2n                                               t = +-2/3 +2n