Quadratic Sequences - How to find the formula for the n-th term

Quadratic sequences, how to find the formula for the n-th terlm, using the difference method. Quadratic sequences of numbers are characterized by the fact that the difference between terms always changes by the same amount. Consequently, the difference between "the differences between the sequence's terms" is always the same. We say that the second difference is constant. Check out the page this Tutorial was made for: http://www.radfordmathematics.com/algebra/sequences-series/difference-method-sequences/quadratic-sequences.html