1 + sin 2x - sin x = cosx
sin^2x + 2sinxcosx+ cos^2x - sinx - cosx = 0
(sinx + cosx)^2 - (sinx + cosx) = 0
(sinx + cosx)*(sinx + cosx - 1)=0
1) sin x + cos x = 0
tgx + 1 =0
tgx = -1
x= - pi/4+pik, k∈Z
2) sinx + cosx = 1
√2*sin(pi/4 + x)= 1
sin(pi/4 + x)= √2/2
pi/4+x=pi/4+2pik
x=pi/4-pi/4+2pik
x=2pik, k∈Z
pi/4+x=3pi/4+2pik
x=3pi/4-pi/4+2pik
x=pi/2+2pik, k∈Z