So I'm going to try to write it in different ways. And the chain rule tells us that if you have a situation like this, then the derivative, f prime of x, and this is something that you will see in your textbooks, so this is going to be the derivative of this whole thing with respect to u of x, so we could write that as v prime of u of x, v prime of u of x, times the derivative of u with respect to x, times u prime of x. This right over here, this is one expression of the chain rule. And so how do we evaluate it in this case? Let me color code it in a similar way. So the v function, this outer thing that just takes things to the third power, I'll put in blue. So f prime of x, another way of expressing it, and I'll use it with more of the differential notation.