证明tan^θ-sin^2θ=tan^2θsin^2θ证明（1）tan^θ-sin^2θ=tan^2θsin^2θ（2）sin^4x+cos^4x=1-2sin^2cos^2x（31-tan^2x/1+tan^2x=cos^2x-sin^2x

证明tan^θ-sin^2θ=tan^2θsin^2θ证明（1）tan^θ-sin^2θ=tan^2θsin^2θ（2）sin^4x+cos^4x=1-2sin^2cos^2x（31-tan^2x/1+tan^2x=cos^2x-sin^2x 证明：tanθ-(1/tanθ)=-2/tan2θ 证明：tanθ/2-1/(tanθ/2)=-2/tanθ 证明(tan^2-sin^2)cot^2=sin^2 证明tan^2x-sin^2x=tan^2 sin^2x 证明:(tan^2)x-(sin^2)x=(tan^2)x(sin^2)x 证明：tan^2a-sin^2a=tan^2*sin^2a 证明：tan^2角-sin^2角=tan^2角sin^2角 证明tan^2-sin^2=tan^2sin^2急用! 数学证明sin^2 αtan^2 α=tan^2 α-sin^2 α 求证tan^2θ-sin^2θ=tan^2θsin^2θ 证明 tanα=2tanβ 证明1-2cos^2θ/tanθ-cotθ=sinθcosθ 证明 2sin（П+θ）cosθ-1/1-2sin^2θ =tan(9П+θ)-1/tan(П+θ）+1 证明:tanθsinθ = secθ-cosθ ) 求tanθ=sinθ/cosθ的证明 证明tanα/2=1-cosɑ/sinɑ 证明tan a/2=sin a/(1+cos a)