Let's just pick some points on this curve of y is equal to e to the x, and think about what the slope of the tangent line is, or what the derivative looks like. And so let's say when y is equal to one, or when e to the x is equal to one, this is the case when x is equal to zero, well, the slope of the tangent line looks like it is one, which is curious, because that's exactly the value of the function at that point. What about when e to the x is equal to two, right over here? Well, here, let me do it in another color, the slope of the tangent line sure looks pretty close, sure looks pretty close to two. What about, what about when e to the x is equal to 1 1⁄2? So that's happening right about here. Well, it sure looks like the slope of the tangent line is about 1 1⁄2.