Answer:
Quadratic: y = -x^2 + 7
Explanation:
Diff Diff Diff in
in x x y in y Differences
-2 3
1 -1 6 3
1 0 7 1 -2
1 1 6 -1 -2
1 2 3 -3 -2
The differences in x are all 1. The differences in y are not equal, so it is not linear. The differences in the differences in y are all 2. It is quadratic.
Try: y = -x^2 + 7
x = -2:
y = -(-2)^2 + 7 = -4 + 7 = 3
You get (-2, 3) which is a given point.
Now try the same x value with the other quadratic equation.
y = x^2 + 7
x = -2:
y = (-2)^2 + 7 = 4 + 7 = 11
You get (-2, 11) which is not a given point.
Answer:
Quadratic: y = -x^2 + 7