Remember, this right over here, this right over here is our goal. We essentially want to figure out the derivative of this with respect to x. So I'm assuming you've had a go at it, so let's work through this together. So if y is the inverse sine of x, that's just like saying that, that's equivalent to saying that sine of y is equal to x. Sine of y is equal to x. So now we have things that we're a little bit more familiar with, and now we can do a little bit of implicit differentiation. We could take the derivative of both sides with respect to x.