sinx/(1+cos)=1/2则tanx/2=
问题描述：
sinx/(1+cos)=1/2则tanx/2=
答
sinx/(1+cosx)
=2sin(x/2)cos(x/2)/2cos(x/2)cos(x/2)
=tan(x/2)
所以, tan(x/2) = 1/2
答
令a=x/2
sinx/(1+cosx)
=sin2a/(1+cos2a)
=2sinacosa/(1+2cos²a-1)
=2sinacosa/2cos²a
=sina/cosa
=tana=1/2
即tanx/2=1/2