cosx = (cosx/2- sinx/2)^2 - 1 x (pi/2, 2pi)

Question

cosx = (cosx/2- sinx/2)^2 - 1 x (pi/2, 2pi)

Answer 1

(cos x/2- sin x/2)^2 = cos^2x/2-2sinx/2*cosx/2+sin^2x/2=1-sinx

1-sinx-1=-sinx

cosx=-sinx

-tgx=1

tgx=-1

x=3pi/4+pi*k k-целое число