【sin(x/2)=2cos(x/2),tan(x/2)=(sinx/2)/(cosx/2)=1/2】请问这一步是怎么算
【sin(x/2)=2cos(x/2),tan(x/2)=(sinx/2)/(cosx/2)=1/2】请问这一步是怎么算
请问怎么证明sinX+sin(X+Y)+sin(X+2Y)/cosX+cos(X+Y)+cos(X+2Y)=tan(X+
求证 sin^2x/(sinx-cosx)-(sinx+cosx)/tan^2 x-1=sinx+cosx
(2sinx*cosx)/sin^2x+cos^2x=(2tanx)/tan^2x+1 怎么推导的?
化简sin^4x/sinx-cosx - (sinx+cosx)cos^2x/tan^2x-1
已知(2sinx+cosx)(sinx+2cosx-3)=0 求sin 2x+cos 2x/tan 2x
(sin^x/sinx-cosx)-sinx+cosx/tan^2x-1
1-cosX/sinX=tan(X/2) 请问怎么证明,
sinx+cosx/sinx-cosx=2 求sinx/cos^3x +cosx/sin^3x
SinX+1-cosX/sinX-1+cosX=1+tan(X/2)/1-tan(X/2) 请问怎么证明,
tan(3x/2)-tan(x/2)-2sinx/(cosx+cos(2x))=?
证明成立:[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).