1/cos^2x-3/cosx+2=0

Question

1/cos^2x-3/cosx+2=0

Answer 1

1/cos^2x-3/cosx+2=0|cos^2x
1-3cosx+2cos^2x=0
2y^2-3y+1=0
y1=1;y2=1/2
cosx=1 или cosx=1/2
x=2Пk;k∈Z    x=+-П/3+2Пk;k∈Z
Ответ 2Пk;+-П/3+2Пk;k∈Z