Our interval, let's see, this point right over here where the square root of x is equal to 1, that's just going to be x equals 1. This is just x equals 1 over here. We said that we would do this all the way until x equals 4. This was kind of our end of our interval. This is until x is equal to... Let me be careful. This is the x-axis right over here. This is the x-axis right over here, all the way until x equals 4.