And so, just eyeballing it, is it the case that the slope of the tangent line of e to the x is the same thing, is e to the x? And I will tell you, and this is an amazing thing, that that is indeed true. That if I have some function, f of x, that is equal to e to the x, and if I were to take the derivative of this, this is going to be equal to e to the x as well. 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.