(cos X-1)^2+sin^2X=2-2cos X 证明题(要过程)
证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
证明COS(X+Y)COS(X-Y)=COS^2X-SIN^2Y
证明成立:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).
2cos x (sin x -cos x)+1
证明1-tan^2x/1+tan^2x=cos^2x-sin^2x
证明下列恒等式: (1)2sin(2/π+x)cos(2/π-x)*cosθ+(2cos^2x-1)*sinθ=sin(
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
f(X)=sin^4x-cos^4x+cos^2x 判断奇偶性 要具体过程的.
数学函数证明题cos^2x+cos^2(x+a)-2cosxcosacos(x+a)=sin^2a
三角函数证明及化简题1.证明sin^6x+cos^6x=(sin^2x+cos^2x)(cos^4x-cos^2xsin
证明1/sin^x+1/cos^2x-1/tanx^2x=2+tan^2