1+sin2x+cos2x/1+sin2x-cos2x
=（2sinxcosx+2cos^2x）/(2sinxcosx+2sin^2x)
=(tanx+1)/(tanx+tan^2x)
=(3+1)/(3+9)
=1/3
1+cos2x=2cos^2x
1-cos2x=2sin^2x