Question

cos2x+cos^2(3п/2-x)=0,25

Answer 1

cos2x+cos^2(3п/2-x)=0,25
cos2x+(-sin)^2(x)=0,25
1 - 2sin^2 (x) + sin^2(x) = 0.25 
- 2sin^2 (x) + sin^2(x) = - 0.75
- sin^2 (x) = - 0.75
sin^2 (x) = 3/4
1. sinx = sqrt(3)/2
x = (-1)^k arcsin (sqrt(3)/2) + Pi*k, k принадл Z
x = (-1)^k Pi/3 + Pi*k, k принадл Z
2. sinx = -sqrt(3)/2
x = (-1)^n arcsin (-sqrt(3)/2) + Pi*n, n принадл Z
x = (-1)^(n+1) Pi/3 + Pi*n, n принадл Z