证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
证明(1-2sin x cos x )/(cos^2x-sin^2x)=(1-tan x)/(1+tan x)
证明1-tan^2x/1+tan^2x=cos^2x-sin^2x
证明 (tan xsin x)/(tan x-sin x)-(1+cos x)/sin x
证明1/sin^x+1/cos^2x-1/tanx^2x=2+tan^2
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
证明:(1 + tan x) / (sin x + cos x) = 1 / cos x
求极限x趋于0时(1-cos(x/2))x / (tan x-sin x)
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
证明1/sin²x+1/cos²x-1/tan²x=2+tan²x限今天速度
证明(tan^2x-cot^2x)/(sin^2x-cos^2x)=sec^2x+csc^2x
证明(tan^2x-cot^2x)/(sin^2x+cos^2x)=sec^2x+csc^2x