证明1-2sinxcosx/cos^2x-sin^2x=cos^2x-sin^2/1+2sinxcosx

证明：(1+2sinXcosX)/(sin^2X-cos^2X)=(tanX+1)/(tanX-1) 1).证明1-2sinxcosx/cos²x-sin²x=1-tanx/1+tanx sin²X-sinxcosx+2cos²x= sin²x+sinxcosx+2cos²x= sin^2xtanx+cos^2x/tanx+2sinxcosx-(1+cosx/sinxcosx)化简 已知函数f(x)=1/2cos^2x-sinxcosx-1/2sin^2x 已知函数f(x)=cos^2x-sin^2x+2根号3sinxcosx+1 y=1/2cos^2x+sinxcosx+3/2sin^2x 求单调区间 求证(1-2sinxcosx)/(cos^2x-sin^2x)=(1-tanx)/(1+tanx) 求证1+2sinxcosx/cos^2x-sin^2x=1+tanx/1-tanx （cos^2x-sin^2x)/(1-2sinxcosx)=(1+tanx)/(1-tanx) sin^2x+2sinxcosx-3cos^2x=1 求sinx