But if you think about it, this is the same thing as, if you're not familiar with sigmation, this is a good kind of thing to know in general, just a little bit of intuition, that this is the same thing as, I'll do it here to have space, as the sum from i is equal to 1 to n of the first term, x sub i squared minus, and actually we can bring out the constant terms. You just can't take, when you're summing, the only thing that matters is the thing that has the ith term. So in this case, it's x sub i, so x sub 1, x sub 2. So that's the thing that you have to leave on the right hand side of the sigmonotation. And if you've done the calculus playlist already, sigmonotation is really, it's kind of like a discrete integral on some level. Because in an integral, you're summing up a bunch of things, you're multiplying them times dx, which is a really small interval, but here you're just taking a sum. And that's what we showed in the calculus playlist, that an integral actually is kind of this infinite sum of infinitely small things, but I don't want to digress too much, but this was just a long way of saying that the sum from i equals 1 to n of the second term is the same thing as minus 2 times mu of the sum from i is equal to 1 to n of x sub i.