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. Negative 2 times sine of 0, that's going to be 0. And then plus 4 times sine of 2 times 0, that's still sine of 0. So that's still going to be 0.