If someone asked you just what f of x was, well, that would be natural log of x. But f of g of x is natural log of our g of x, which is natural log of sine of x. So that's the key first thing. Always make sure whether you're gonna use, especially with these transcendental functions, that hey, if this is a composition, you've gotta use the chain rule, not the product rule. It's not the product. Now sometimes you have a combination. You have a product of compositions, and then things get a little bit more involved.