So here, this is not differentiable. And even intuitively, we think of the derivative as the slope of the tangent line, and you could actually draw an infinite number of tangent lines here. It's one way to think about it. You could say, well, maybe this is the tangent line right over there, but then why can't I make something like this the tangent line? That only intersects at the point C comma zero, and then you could keep doing things like that. Why can't that be the tangent line? And you could go on and on and on.