For any other x value, it is differentiable. But right at x equals one, we've talked in other videos how we aren't differentiable there. And then we can use this local linearity idea to test it as well. And once again, this is not rigorous mathematics, but it is to give you an intuition. No matter how far we zoom in, we still see this sharp corner. It would be hard to construct the only tangent line, a unique line that goes through this point one comma zero. I can construct an actual infinite number of lines that go through one comma zero, but that do not go through the rest of the curve.