product of two consecutive integers is even

Can someone prove for me that n(n + 1) where n is an arbitrarily chosen integer can be represented as 2k where k is an integer? It was on the board today, and apparently I need to know it, but I was sleeping.

>>11

Actually, >>10 was right - you do need induction. What >>4 was doing was "plug in the integer into this eqn if it's even, and plug it in the other if it's odd"

You need to prove it's true for the entire set of integers, which is where induction comes into play.