Question 589832
We want to prove that


*[tex \LARGE \frac{\sin^2 \theta}{1 - \cos \theta} = 1 + \cos \theta] (where cos theta is not equal to 1)


This is true if and only if


*[tex \LARGE \sin^2 \theta = (1 - \cos \theta)(1 + \cos \theta)] (multiplying both sides by 1 - cos(theta)).


*[tex \LARGE \sin^2 \theta = 1 - \cos^2 \theta], adding cos^2 (theta) to both sides yields the Pythagorean identity. Hence the original statement is true.