求证：tan x/2=sin x/(1+cos x)

求证：tan x/2=sin x/(1+cos x) 求证：1-sin(x)=cos(x)*tan(x/2) 求证：(sin x+cos x)(1-tan x)=(2sin x)/(tan2x) 求证tan^x-sin^2x=tan^2x*sin^2x 求证:(sin 2x /(1-cos 2x) )·(sin x /(1+sin x))=tan (π/4-x/2). 求证：1-2sinxcosx/cos方x-sin方x=1-tan/+tan 求证；1-2sin Xcos X/cos2 X-sin2 X=1-tan X/1+tan X 求证(3-sin^4 x-cos^4 x)/2cos^2 x=1+tan^2 x+sin^2 x 证明tan^2x=2*tan^2y+1,求证sin^2y=2sin^2x-1 tan方x=2tan方y+1,求证sin方y=2sin方x-1 求证 （1—tan^2X)/(1+tan^2X)=cos^2X—sin^2X 求证:Sin^2 x / (sinx-cosx) - (sin x + cos x)/(ta求证:Sin^2 x / (sinx-cosx) - (sin x + cos x)/(tan^2-1) = sin x + cos x 已知sin（x+y）=1,求证：tan（2x+3y）=tany 求证 sin^2x/(sinx-cosx)-(sinx+cosx)/tan^2 x-1=sinx+cosx 求证sin^4x-cos^4x=2sin^2x-1如果可以的话把tan^2x-sin^2x=tan^2xsin^2x帮求证一下 求证sin^2x/sinx-cosx-(sinx+cosx)/(tan^2-1)=sinx+cosx谢谢GGJJ 求证tan(x+y)*tan(x-y)=tan^2x-tan^2y/1-tan^2xtan^2y 求证 (1/sin^2 x) + (1/cos^2 x) - （1/tan^2 x）= 2 + (tan^2 x)怎么证明啊……?