(2) Bring x=9 into (1) and calculate Y = 2.45 > 2.43, then you can bring y=0 in again. If the positive value of X is greater than 18, it will be out of bounds.

(3) Let y=a(x-6) square +h, and bring in (0,2) to find 36a+h=2. Judging from the meaning of the question, it is 9a+h > 2.43 144a+h ≤ 0, which means that h is greater than or equal to 8/3.