2sin^2x-1=0[0,2pi)

2 sin ^ 2 ( x ) - 1 = 0

2 sin ^ 2 ( x ) = 1 Divide both sides by 2

sin ^ 2 ( x ) = 1 / 2

sin ( x ) = ± 1 / sqrt ( 2 )

sin ( x ) = 1 / sqrt ( 2 )

for

x = pi / 4 and x = 3 pi / 4

sin ( x ) = - 1 / sqrt ( 2 )

for

x = 5 pi / 4 and x = 7 pi / 4