高一三角函数化简 sin^2(α)/((sinα)－(cosα))+(cosα)/(1－tan(α))

sin^2(α)/((sinα)－(cosα))+(cosα)/(1－tan(α)) = sin^2(α)/((sinα)－(cosα))+(cosα)/(1－sin(α)/cos(α)) =sin^2(α)/((sinα)－(cosα))+cos^2(α)/(cos(α)－sin(α)) =(sin^2(α)-cos^2(α))/((sinα)－(cosα)) =((sinα)－(cosα))((sinα)+(cosα))/((sinα)－(cosα)) =sinα+cosα