Is this consistent with what we know about derivatives and slopes and all the rest? Well, let's look at our function. What is the slope of the line, or the tangent line, right at this point? Well, the slope of this right over here, this has slope 1 continuously, or it has a constant slope of 1. Slope is equal to 1 no matter what x is, it's a line. And for a line, the slope is constant. So over here, the slope is indeed 1.