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

Answer 1

B. an = -2 + an-1

Answer 2

It's geometric, so there's gotta be some multiplication involved.

Answer 3

I'm pretty sure it is D. If you take a2 divided by a1, and a3 divided by a2, you get a common ration of -4 for each. And since it is geometric, we are multiplying between each (so that rules out option A, I think).