They're of course the same thing. But anyway, now we can just simplify it. This is going to be equal to, this is going to be equal to, we could write this either as e to the x times cosine of x, times cosine of x, minus e to the x, e to the x, times sine of x, times sine of x. Or if you want, you could factor out an e to the x. This is the same thing as e to the x times cosine of x minus sine of x, cosine of x minus sine of x. So hopefully this makes the product rule a little bit more tangible. And once you have this in your tool belt, there's a whole broader class of functions and expressions that we can start to differentiate.