Question

6*sin^2*x+5*cos(x)-7=0

Answer 1

6-6cos^2 x + 5cos x -7 = 0

6 cos^2 x - 5cos x +1=0

cos x =1/2 => x = +-pi/3+2pi*n,n принадлежит Z

cos x = 1/3 => x=+-arccos(1/3) +2pi*n