So if that was a two there, and if you don't want to change the value of the integral, you put the 1 1 2 right over there. So now you could either do u substitution explicitly, or you could do it in your head, where you said u is equal to negative x squared, and then du will be negative two x dx, or you can kind of do this in your head at this point. So I have something and its derivative, so I really could just integrate with respect to that something, with respect to that u. So this is going to be 1 1 2, this 1 1 2 right over here. The antiderivative of this is e to the negative x squared, and then of course I might have some other constant. I'll just call that c two. And once again, if this part over here, what I just did seems strange, the u substitution, you might want to review that piece.