Question

How do you find a formula of the nth term for this sequence: 1, 3, 9, 27, 81, …?

Answer 1

Apparently the common ratio is `3`

Explanation:

The 2nd term is `3`, the 3rd=`9=3^2`, the 4th=`27=3^3`
To get to the `n`th term we will have to multiply `n-1` times by `3`

Or:
`t_n=3^(n-1)`

Watch out!
Usually the first term is called `t_0`, which would change the formula into `t_n=t_0*3^n=1*3^n`.
But then the `n`th term would be `t_(n-1)` and all would still be correct. Watch this when you're doing a test!