9.2k views
2 votes
Which formula can be used to describe the sequence?

-, −4, −24, −144,...

User Dgiugg
by
5.0k points

2 Answers

7 votes
Can't make out your first term, so I will assume that it is -4.

The common ratio of this geom. seq. is 6.

Thus, a(n) = -4(6)^(n-1)

Check: if n = 3, do we get -144 as the 3rd term?

a(3) = -4(6)^(3-1) = -4(6)^2 = -4(36) = -144. YES.
User Mark Mucha
by
5.4k points
6 votes

Answer: The formula that can be used to describe the sequence is given by
a_(n+1)=-6* a_n

Explanation:

Since we have given that

-, −4, −24, −144,...

Here, we can see that

-4 × 6 = -24

-24 × 6 = -144

So,
a_1=-4

So, the recursive formula will be


a_(n+1)=-6* a_n

Hence, the formula that can be used to describe the sequence is given by
a_(n+1)=-6* a_n

User Manjunath Rao
by
5.4k points