Question

What is the recursive formula for the sequence?

8, 10, 12, 14, . . .

1. an=an-1+2,where a,=8
2. an=an-1+2,where a,=16
3. an-1-2 where a,=2
4. an=an-1-2, where a,=8

Answer 1

Answer: option 1.

$a_n=a_{n-1}+2$,

where

$a_{1}=8$

Explanation:

10 = 8 + 2
12 = 10 + 2
14 = 12 + 2

So, you see that, starting with 8, each next may be obtained by adding up 2 to the previous term, which is what the given formula returns.

$a_n$             is the actual term

$a_{n-1}$          is the previous term