
Inha C. answered 03/06/21
Math tutor with 10+ TA classes and 3+ years of tutoring experience
Your quadratic function passes through (0, 3), which means when x = 0, f(x) = 3. When x is 0, the x2 and x terms are all going to be zero. So the constant must be +3, not -3. This rules out (B).
Now I'm going to plug "when x = 1, f(x) = 2" into (A), (C), and (D).
(A): 2 = 2 + 1 + 3, doesn't make sense.
(C): 2 = 2 - 1 + 3, also doesn't make sense.
(D): 2 = -2 + 1 + 3
So the answer is (D).
I just want to check if (D) also satisfies "when x = 3, f(x) = -12" in case.
It gives: -12 = -18 + 3 + 3. Still sounds fine.