Mathematic Problems
tg2x-sin2x
tg2x-sin2x
=sin2xcos2x-sin2x
=sin2x-cos2x·sin2xcos2x
=sin2x1-cos2xcos2x
=sin2x·sin2xcos2x
=tg2x·sin2x
tg2x-sin2x=tg2x·sin2x