证明tan^2-sin^2=tan^2sin^2急用!

证明(tan^2-sin^2)cot^2=sin^2 证明 tanα=2tanβ 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 证明tanα/2=1-cosɑ/sinɑ 证明tan a/2=sin a/(1+cos a) 已知tan(a+b)=2tan a 证明 3sinb=sin(2a+b) 证明tan(x+y)+tan(x-y)=sin2x/cos^2x-sin^2y sin(α+β)=1 证明tan(2α+β)+tanβ =0 证明：(1+tan a+cot a)/(1+tan^2 a+tan a)-cot a/(1+ tan^2 a)=sin a*cos a （1+tanα+cotα)/(1+tan^2α+tanα)-cotα/(1+tan^2α)=sinα乘cosα麻烦帮忙证明下, 高1数学3角函数证明.tan^2-sin^2=tan^2·sin^2.题目就是这样tan平方减sin平方=tan平方乘sin平方,要证明, 证明tan^2x=2*tan^2y+1,求证sin^2y=2sin^2x-1 证明:1-2sinα cosα/cos^2α -sin^2α=1-tanα/1+tanα