19nuranij97 1) 3-3cosx=2sin^2x
3-3cosx=2-2cos^2x
3-3cosx-2+2cos^2x=0
2cos^2x-3cosx+1=0
cosx=t
2t^2-3t+1=0
D=9-8=1
t1=(3-1)/4=1/2
t2=(3+1)/4=1
cosx=1/2
x=п/3+2пk
cosx=1
x=2пk