Or another way of saying it, the derivative with respect to x of e to the x is equal to e to the x. And that is an amazing thing. In previous lessons or courses, you've learned about ways to define e. And this could be a new one. E is the number that where if you take that number to the power x, if you define a function or expression as e to the x, it's that number where if you take the derivative of that, it's still going to be e to the x. And what you're looking here, this curve, it's a curve where the value, that's y value, at any point is the same as the slope of the tangent line. If that doesn't strike you as mysterious and magical and amazing just yet, it will. Maybe tonight, you'll wake up in the middle of the night and you'll realize just what's going on.