Question 267031
f(0) = -2
f(1) = -2 + 2(1) = 0
f(2) = 0 + 2(2) = 4
f(3) = 4 + 2(3) = 10
f(4) = 10 + 2(4) = 18
f(5) = 18 + 2(5) = 28
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first differences: 2, 4, 6, 8, 10
second differences: 2, 2, 2, 2
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this is a quadratic model.