(2sinx)/sin(3x)+tanx/tan(3x)=(2sinx)/sin(3x)+(sinx/cosx)/(sin(3x)/cos(3x))=
=((2sinx)/cos(3x)+(sinx/cosx)*(sin(3x)/(cos(3x))) ) /(sin(3x)/cos(3x))=
=(((2sinxcosx+sinx*(sin(3x)))/(cancelcos(3x)*cosx)) ) /(sin(3x)/cancelcos(3x))=
=(( 2sinxcosx+sinx*(sin(3x)) )/cosx)/(sin(3x))=
= (2sinxcosx+sinx*sin(3x))/(sin(3x)cosx)=
sin(3x)=3sinx-4sin^3x
= (2sinxcosx+sinx*sin(3x))/((3sinx-4sin^3x)cosx)=
= (cancel(sinx)(2cosx+sin(3x)))/(cancel(sinx)(3-4sin^2x)cosx)=
= (2cosx+sin(3x))/((3-4sin^2x)cosx)