2sin^2+cos^X/sin^2+cos^2=2tan^2X+1/tan^2X+1 这个是怎么换算过来的
证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
证明1-tan^2x/1+tan^2x=cos^2x-sin^2x
证(1/sin^2x)+(1/cos^2x)-(1/tan^2x)=2+tan^2x
求证 (1—tan^2X)/(1+tan^2X)=cos^2X—sin^2X
(2sinx*cosx)/sin^2x+cos^2x=(2tanx)/tan^2x+1 怎么推导的?
求极限x趋于0时(1-cos(x/2))x / (tan x-sin x)
证明1/sin^x+1/cos^2x-1/tanx^2x=2+tan^2
tan(x+y)tan(x-y)=sin^2x-sin^2y/cos^2x-sin^2y 顺便问一下. tan,sin,
求证:sin^2/(sin-cos) - (sin+cos)/(tan^2 -1) =sin+cos
化简sin^4x/sinx-cosx - (sinx+cosx)cos^2x/tan^2x-1
化简sin(派-x)+sin(派+x)-cos(-x)+cos(2派-x)-tan(派+x)cot(派-x)