But as we zoom in, we see once again this local linearity. And it's a non-vertical line. And so once again, this is true at any point on this curve, that we are going to be differentiable. So the whole point here is sometimes you might have to zoom in a lot. A tool like Desmos, which I'm using right now, is very helpful for doing that. And this isn't rigorous mathematics, but it's to give you an intuitive sense that if you zoom in sufficiently and you start to see a curve looking more and more like a line, good indication that you are differentiable. If you keep zooming in and it still looks like a hard corner, or if you zoom in and it looks like the tangent might be vertical, well then, some questions should arise in your brain.