And that's what this 1 over pi is going to cancel out with. And you could do u substitution and all the rest if you found something like that useful. But it's in general a good habit, or I guess it's good to be able to do this almost by sight. And you can verify that this derivative is equal to sine of pi x. So the antiderivative of sine of pi x is this. The antiderivative of negative 8x to the third power is negative 8. I'm going to divide it by 4, so negative 2x to the fourth power.