Вопрос по Математике

sin^2(a)+cos^2(a)=1sin(a) = 0,6 => sin^2(a) = 0.36cos^2(a) = 1 - 0,36 = 0,64cos(a) = +-0.8Т. к. 90<a<180, тоcos(a) = -0.8