So the relationship between y and x that goes through this point, we could just set c is equal to zero, so that's equal to zero, that's zero right over there, and so we are left with y squared over two is equal to e to the negative x squared over two. Now we can multiply both sides by two, and we're going to get y squared, y squared, let me do that, so we're going to get y squared is equal to, is equal to e to the negative x squared. Now we can take the square root of both sides, and you could say, well look, y squared is equal to this, so y could be equal to the plus or minus square root of e to the negative x squared, of e to the negative x squared, but they gave us an initial condition where y is actually positive. So we're finding the particular solution that goes through this point, that means y is going to be the positive square root. If this was the point zero, negative one, then we would say y is the negative square root, but we know that y is the positive square root, it's the principal root right over there. Actually let me do that a little bit neater, so we can get rid of, whoops, I thought I was writing in black. So we can get rid of this right over here.