证明：利用二倍角公式 sin2A=2sinAcosA,cos2A=1-2sin²A=2cos²A∴ 1-cosA=2sin²A∴ (SinX+1-cosX)/(sinX-1+cosX)=[2sin(x/2)cos(x/2)+2sin²(x/2)]/[2sin(x/2)cos(x/2)-2sin²(x/2)]分子分母...