Question

What is the recursive formula for this arithmetic sequence -16,-7,2,11,

Answer 1

Hello from MrBillDoesMath!

Answer:

a(n) = -16 when n = 1

a(n) = a(n-1) + 9 when n > 1 ( i.e. n = 2,3,4)

Discussion:

First observation:

-16 + 9 = -7

-7 + 9 = 2

2 + 9 = 11

So the pattern seems to be gotten by addition of 9 to each number. The recursive formula therefore is this:

a(n) = -16 when n = 1

a(n) = a(n-1) + 9 where n > 1 ( i.e. = 2,3,4)

Thank you,

MrB