Question

sin4x/(1-cos2x )=2sin2x

Answer 1

sin4x/(1-cos2x )=2sin2x | *(1-cos2x )

sin4x=2sin2x * (1-cos2x )

sin4x=2sin2x-2sin2x*cos2x

2*sin2x*cos2x=2sin2x-2sin2x*cos2x

2sin2x=4sin2x*cos2x | :2sin2x

2cos2x=1 | :2

cos2x = 1/2

2x=±arccos1/2 + 2pin

2x=±pi/3 +2pin | :2

x=±pi/6 +pin, где n принадлежит z