And the denominator, this is just an exercise in taking derivatives. What's the derivative of the denominator? Derivative of 1 is 0. And derivative of negative cosine of x is just sine of x. So let's take this limit. So this is going to be equal to, well immediately if I take x is equal to 0 in the denominator, I know that sine of 0 is just 0. Let's see what happens in the numerator.