Let's do that. Let's divide the numerator by cosine squared of y and divide the denominator by cosine squared of y, or multiply each of them by 1 over cosine squared of y. What's that going to give us? The numerator, these characters are going to cancel. You're just going to have a 1. The denominator, this times this, that's just going to be equal to 1. Then you're going to have sine squared y over cosine squared y.