Question

What is the explicit rule for this geometric sequence?

a1=−15;an=15⋅an−1



an=−15⋅15n−1

an=−15(15)n−1

an=15(−15)n−1

an=15⋅(−15)n−1

Answer 1

an=1/5⋅(−15)n−1

Explanation:

I think the problem is a1=−15;an=1/5⋅an−1 and not a1=−15;an=15⋅an−1

I took the test :)

Answer 2

I'm not sure if I'm 100% correct but I think it is C

Explanation: