Cos 2x -sin 2x +2sin^2 x +sinx -2cosx=0
cos^2 x-sin^2 x -2sinx cosx+2sin^2 x+sinx -2cosx=0
cos^2 x+sin^2 x -2sinx cosx +sinx-2cosx=0
sinx *(sinx-2cosx) +(sinx-2cosx)+cos^2 x=0
(sinx -2cosx)*(sinx+1) +(1-sin^2 x)=0
(sinx -2cosx)*(1+sinx) +(1-sinx)(1+sinx)=0
(1+sinx)*(siinx-2cosx+1-sinx)=0
1+sinx=0 ili 1-2cosx=0
sinx=-1 cosx=1/2
x=-π/2+2πn x=+-arccos(1/2)+2πn; n-celoe
----------------- x=+-π/3+2πn; n-celoe
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