Use Mathematical Induction to Prove That for All Integers $n \geq 0$

Essay

Use mathematical induction to prove that for all integers $n \geq 0$ ,
$$1 + 3 + 3 ^ { 2 } + \cdots + 3 ^ { n } = \frac { 3 ^ { n + 1 } - 1 } { 2 } .$$