Write the recursive formula for the geometric sequence.

a1 = -2 a2 = 8 a3 = -32

A. an = -4 + an-1
B. an = -2 + an-1
C. an = -2 • an-1
D. an = -4 • an-1

Question

Write the recursive formula for the geometric sequence.

a1 = -2  a2 = 8  a3 = -32

A. an = -4 + an-1
B. an = -2 + an-1
C. an = -2 • an-1
D. an = -4 • an-1

terenzreignz · Answer

If you're still there... think about it :)
What did you multiply to -2 so that you get 8?
What did you multiply to 8 so that you get -32?

anonymous · Answer

-4?

terenzreignz · Answer

That's right :)
Every term is the previous term multiplied by -4.
Does that answer the question?

anonymous · Answer

thank you so much. i gave you a medal.

terenzreignz · Answer

No problem :)
You got it yourself, you just needed a little nudge ;)