That is my x-axis. So defined this way, f of x is equal to x plus 3. So if this is 1, 2, 3, we have a y-intercept at 3, and then the slope is 1. The slope is 1. But it's defined for all x's, except for x is equal to 2. So this is x is equal to 1, x is equal to 2. So when x is equal to 2, it is undefined.