Well, now we just have to take the antiderivative. And this is going to be equal to pi times, antiderivative of x to the fourth is x to the fifth over 5. Antiderivative of 4x to the third is actually x to the fourth. So this is going to be minus x to the fourth. You can verify that. Derivative is 4x. And then you decrement the exponent 4x to the third.