Question

What is the recursive formula for this geometric sequence?
-3, -21, -147, -1029, ...

Answer 1

Explanation:

First of all the first term is a1 and that's equal to -3

Every term is multiplied by 7

So the recursive formula is

an = 7*a_(n-1)

a2 = 7*a_(1 -1)

a2 = 7*-3

a2 = - 21

Now try a_4

a_4 = 7*a_3

a_3 = -147

a_4 = 7*(-147)

a_4 = -1029