[(1+tanx)cos^2x]/[cos2x+sin2x]=1/2+1/[2sqrt(2)sin(2x+π/4)]怎么推导出来的?

(tanx+1/tanx)cos^2 x等于 (tanx+1/tanx)cos^2 x等于 [tanx+(1/tanx)]cos^x ﹙tanx+1/tanx)cos^2x等于 y=(tanx-1)cos^2x最大值y=(tanx-1)cos²x最大值 提问数学难题求证：sin^2x*tanx+cos^2x/tanx+2sinx*cosx=tanx+1/tanx tanx/(cos^2)x dx 证明1-2sinxcosx/cos^2x-sin^2x=1-tanx/1+tanx 证明：(1+2sinXcosX)/(sin^2X-cos^2X)=(tanX+1)/(tanX-1) 求证1+2sinxcosx/cos^2x-sin^2x=1+tanx/1-tanx 求证(1-2sinxcosx)/(cos^2x-sin^2x)=(1-tanx)/(1+tanx)SOS! （cos^2x-sin^2x)/(1-2sinxcosx)=(1+tanx)/(1-tanx)证明题 求证:(1-2sinxcosx)/(cos^2x-sin^2x)=(1-tanx)/(1+tanx) 1-2sinx cosx /COS^2X-SIN^2X =1-tanx/1+tanx 求证 若tanx/tanx-1=-1 求sin(π/2+x)cos(3π/2-x) 求证(1-2sinxcosx)/(cos²x-sin²x)=(1-tanx)/(1+tanx) 化简sin^x*tanx+cos^x*1/tanx+2sinx*cosx 已知tanx=2,则sin2x/(1+cos^x)