2sin²x + cos5x = 1
cos5x=cos^2x-sin^2x
cos5x=cos2x
cos5x-cos2x=0
-2sin(7x/2)*sin(3x/2)=0
sin(7x/2)=0
(7x/2)=πn, n ∈ Z
x=(2/7)πn, n ∈ Z
sin(3x/2)=0
(3x/2)=πk, k ∈ Z
x=(2/3)πk, k ∈ Z
О т в е т.(2/7)πn, n ∈ Z; (2/3)πk, k ∈ Z