All right, let's just follow her work. So here she's trying to take the first derivative. So you would apply the chain rule. It would be four times x minus two to the third power times the derivative of x minus two, which is just one. So this checks out. Then you take the derivative of this. It would be three times four, which would be 12 times x minus two to the second power times the derivative of x minus two, which is just one, which is exactly what she has here, 12 times x minus two to the second power.