2(1-sin^2x)+2√2sinx-3=0
2-2sin^2x+2√2sinx-3=0
2sin^2x-√8sinx+1=0
D=8-4*2=0
x= -b/2a = √2/2
sinx= √2/2
x=pi/4+2pik, k∈Z
x=3pi/4+2pik, k∈Z
