化简(1+tan^2x)cos^2x
化简tan(3x/2)-tan(x/2)-sinx/(cos(3x/2)*cos(x/2))
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
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)
求极限x趋于0时(1-cos(x/2))x / (tan x-sin x)
化简:sin(2派-x)tan(派+x)cot(-x-派)/tan(3派-x)cos(派-x)
化简2cos*2-1 / 2tan(π/4-x)sin*2(π/4+x)
化简[sin(180+x)-tan(-x)+tan(-360-x)]/[tan(x+180)+cos(-x)+cos(-
1.化简:⑴【Cos(x—π) tan(x—2π) tan(2π—x)】/【sin(π+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