证明tan^2x-sin^2x=tan^2x*sin^2x解sin^2x sin^2x--------- - -----------cos^2x 1等于sin^2x sin^2x--------- - -----------cos^2c cos^2x+sin^2x接下来还能做吗?这道题还有其他证法吗?怎么能等式两边同除呢？这是证明题，证

证明:(tan^2)x-(sin^2)x=(tan^2)x(sin^2)x 证明tan^2x-sin^2x=tan^2 sin^2x 证明tan(x+y)+tan(x-y)=sin2x/cos^2x-sin^2y 证明tan^2x=2*tan^2y+1,求证sin^2y=2sin^2x-1 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 sin(2x) = (2*tan(x))/(1+tan(x)^2)有这个公式吗?求证明 求证tan^x-sin^2x=tan^2x*sin^2x 初三或者高中证明题,tan sin cos的东东证明,tan(X/2)=(1-cosX)/sinX 证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)谢谢谢谢 急 证明1/sin^x+1/cos^2x-1/tanx^2x=2+tan^2 证明(tan^2x-cot^2x)/(sin^2x+cos^2x)=sec^2x+csc^2x (1+tan(x))/sin(2x)不定积分 tan(x)=2求sin(x)cos(x)=? tan x=2,求 sin x * cos x=? 求证：tan x/2=sin x/(1+cos x) 求证：1-sin(x)=cos(x)*tan(x/2) tan(x+y)tan(x-y)=sin^2x-sin^2y/cos^2x-sin^2y 顺便问一下. tan,sin,cos是什么意思? 已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x