Question

Please help!!! please show the work

Find the first four terms of a geometric sequence with the following explicit formula: An = 3 n-1

Answer 1

The first four terms are 1,3,9,27

Explanation:

The explicit formula for the sequence is

`A_n=3^(n-1)`

To find the first term of the sequence, we substitute
`n=1`

`A_1=3^(1-1)`

`A_1=3^0`

`A_1=1`

To find the second term of the sequence, we substitute
`n=2`

`A_2=3^(2-1)`

`A_2=3^1`

`A_2=3`

To find the third term of the sequence, we substitute
`n=3`

`A_3=3^(3-1)`

`A_3=3^2`

`A_3=9`

To find the fourth term of the sequence, we substitute
`n=4`

`A_4=3^(4-1)`

`A_4=3^3`

`A_4=27`