(cos3x/sinx)+(sin3x/cosx)

Question

(cos3x/sinx)+(sin3x/cosx)

Answer 1

(cos3x)/(sinx)+sin3x)/(cosx)=(cos3x*cosx+sin3x*sinx)/(sinx*cosx)=
=cos(3x-x)/(0,5sin2x)=(2cos2x/(sin2x)=2ctg2x