Differentiable at X is equal to C. So let me give a few examples of a non-continuous function. And then think about would we be able to find this limit? So the first is where you have a discontinuity. Our function is defined at C. It's equal to this value. But you can see as X becomes larger than C, it just jumps down and shifts right over here. So what would happen if you were trying to find this limit? Well, remember, all this is is a slope of a line between when X is some arbitrary value.