So the range, the y values that this is going to take on, y is going to be greater than four. It's not ever gonna be equal to four, so I'll do, it's going to be greater than four, that's gonna be the bottom end of my range, and at the top end of my range, I will be equal to six. Six is the largest value that I am going to take on. Another way I could have written this is four is less than y, is less than or equal to six. Either way, this is a way of describing the range, the y values that the solution will take on for x being greater than or equal to zero. If they said for all x's, well, then you might have been able to go back this way and keep going, but they're saying the range of the solution curve for x is greater than or equal to zero so we won't consider those values of x less than zero. So there you go.