# Geometric sequences

• Apr 28th 2009, 07:48 AM
14041471
Geometric sequences
"We define the sequence a recursively by setting a_1 = 10 and a_(i+1) = a_i + 4 for all i>= 1. Give the first five terms of this sequence"

I know a_1 = 10, i'm not sure what I have to change in a_2 a_3..
• Apr 28th 2009, 08:08 AM
earboth
Quote:

Originally Posted by 14041471
"We define the sequence a recursively by setting a_1 = 10 and a_(i+1) = a_i + 4 for all i>= 1. Give the first five terms of this sequence"

I know a_1 = 10, i'm not sure what I have to change in a_2 a_3..

$a_1 = 10$

$a_2 = a_{1+1} = a_1 + 4 = 14$

$a_3 = a_{2+1} = a_2 + 4 = 18$

and so on

By the way: To me this isn't a geometric sequence ???