证明1/sin^x+1/cos^2x-1/tanx^2x=2+tan^2

怎么证明2(1-sin x)(1+cos x)=(1-sin x+cos x)^2 证明一个sin&cos的等式证明 1+sin^2(x)+sin^4(x)+sin^6(x)=[1-sin^8(x)]/[cos^2(x)] 证明：sin^2x+cos^2x=1 (cos X-1)^2+sin^2X=2-2cos X 证明题(要过程) 1-(sin^6x+cos^6x)=3sin^2xcos^2x 如何证明? 证明成立：[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x). 证明1-sin^6x-cos^2x/1-sin^4x-cos^4x=3/2 一道三角函数证明题sin^4 X+cos^4 X=1-2sin^2 X cos^2 X 证明1-2sinxcosx/cos^2x-sin^2x=cos^2x-sin^2/1+2sinxcosx 如何证明sin方x+cos方x=1 证明|sin x|+|cos x|大于等于1 sin^4+sin^2xcos^2x+cos^2x 证明 =1 化简(sin x+cos x-1)(sin x-cos x+1)/sin 2x 证明：(1 + tan x) / (sin x + cos x) = 1 / cos x cos x/sin x+sin x/(1+cos x) 化简. ....[1-(sin x)^2]^1/2=|cos x| 求证明........[1-(sin x)^2]^1/2=|cos x|求证明..... 怎么证明(1/2)sinx=sin(x/2)cos(x/2)怎么证明(1/2)sinx=sin(x/2)cos(x/2) 【高一数学】三角函数的证明题》》》》》》》证明：(sin^4)x+(sin^2)x(cos^2)x+(cos^2)x=1