text: Did you leave out a minus sign between the 1 and the sinx on the left?  If so,\n\nFactor the numerator on the left and cancel the denominator:\n(1-sinx)(1+sinx)/(1-sinx) becomes 1 + sinx\n\nOn the right, split (cscx + 1)/cscx into 2 fractions: cscx/cscx + 1/cscx\n\ncscx/cscx is just 1, and 1/cscx is sinx\n\nSo you get 1 + sinx = 1 + sinx\n\nHope that makes sense.