Bradford T. answered 10/10/21
Retired Engineer / Upper level math instructor
tanxsinx/(tanx-sinx) = (sinx/cosx)sinx/(sinx/cosx -sinx)
= sin2x/(cosx(sinx/cosx - sinx) distribute cosx in denominator
= sin2x/(sinx-sinxcosx) factor denominator
= sin2x/(sinx(1-cosx)) Cancel sinx out of numerator and denominator
= sinx/(1-cosx)