Question

Find a polynomial function f(n) such that f(1), f(2), ... , f(8) is the following sequence.

4, 12, 20, 28, 36, 44, 52, 60
f(n) =

Answer 1

Observing there is a difference of +8 between each f(x).
The slope of this sequence is 8.(y2-y1)/(x2-x1)
Using the point slope equation,
y-y1 = m(x-x1) yields

y = 8x -4 as the answer.