So for example, we could figure out, we could take the derivative at the point one one, use that as the slope of our tangent line, find the equation of the tangent line, and use that equation to approximate values of our function around x equals one. And you might not need to do that for y is equal to x squared, but it could actually be very, very useful for a more complex function. But the big takeaway here, at the point one one, it is displaying this idea of local linearity. And it is also differentiable at that point. Now let's look at another example of a point on a function where we aren't differentiable and we also don't see the local linearity. So for example, let's do the absolute value of x. And let me shift it over a little bit just so that we don't overlap as much.