(sinx+cosx)/(1-tan^2x)+sin^2x/(sinx-coax)=(sinx+cosx)cos^2x/(cos^2x-sin^2x)+sin^2x(sinx+cosx)/(sin^2x-cos^2x)=(sinx+cosx)(cos^2x-sin^2x)/(cos^2x-sin^2x)=sinx+cosx或者进一步化简可得√2sin(x+45°)...或者进一步化简可得√2sin(x+45°) 请问一下，你这里是如何化简的？√2(sinx*(√2/2)+cosx*(√2/2))=√2(sinx*cos45°+cosx*sin45°)=√2sin(x+45°)