1.∫ [sin(2x)]^2 dx=∫(1-cos4x)/2 dx
=(1/2)x-(1/8)∫cos4xd(4x)
=(1/2)x-(1/8)sin4x+C
2.∫(1-tanx)/(1+tanx) dx
=∫(cosx-sinx)/(cosx+sinx) dx
=∫1/(cosx+sinx)d(cosx+sinx)
=ln|cosx+sinx|+C