LHS: sin x/(1-cos x) +(1-cosx)/sin x
=(sinx*sinx+(1-cosx)(1-cosx))/(sinx(1-cos x))->common denominator
=(sin^2 x+1-2cosx+cos^2x)/(sinx(1-cosx)
=(sin^2 x+cos^2x+1-2cosx)/(sinx(1-cosx))
=(1+1-2cosx)/(sinx(1-cosx))
=(2-2cosx)/(sinx(1-cosx))
=(2(1-cosx))/(sinx(1-cosx))
=(2(cancel(1-cosx)))/(sinx cancel((1-cosx)))
=2/sinx
=2*1/sinx
=2 csc x
=RHS