若tan(π/4-θ)=3,则(cos2θ)/(1+sin2θ)等于?

若tan(π/4-θ)=3,则(cos2θ)/(1+sin2θ)等于? 已知tanθ=2,则tan(θ+π/4)= ,cos2θ=已知tanθ=2,则tan(θ+π/4)=cos2θ= 若tan(π-α)=1/3,则cos2α/2sinαcosα+cos2α的值为 若tan θ=3,求sin2θ -cos2θ tanθ=4/3,求cos2θ= cos2α/tan(α+π/4)= 已知tanα=-3/4,则cos2α= 求证：若tan^2 θ=tan^2 α+sec^2 α.则cos2α-2cos2θ=1 tan(π/4+θ)=3,sin2θ-2cos2θ=? tan（π/4/θ）=3,sin2θ-cos2θ等于多少 已知tan( π/4+Θ)=3,求sin2Θ －2cos2Θ的值? 若tanθ=3,则sin2θ-cos2θ的值 若cos2α=m 则tan(α+π/4)=RT tan(α+π/4)=2,则cos2α+3sin^2α+tan2α=? tan(π/4+θ)+tan(π/4-θ)=4,cos2θ=? 设 tan（π/4+θ）=3 求(1+sin 2θ-cos2 θ)/(1+sin2 θ+ cos2 θ)的值 tan（π/4+α）=k 求cos2α 若tanβ=3,sin2β-cos2β=