Question

ax^3+bx^2+cn, find a, b, and c???

Answer 1

this should equal sum of numbers from i=one to n of i squared. For example S(1) is 1, S(2) is 5, S(3) is 14

Answer 2

So S=ax^3+bx^2+cn?

Answer 3

If that is the case, plug in each value for x. You get 3 eqns, 3 unknowns. Solve it!