The sequence below is a geometric sequence. What is the common ratio for this sequence?

Question

What is the common ratio for this sequence?

An = -1/2 (3)^n+1

Answer 1

common ratio is 3

but you have the formula slightly off. Maybe a typo

it should be: an=(-1/2)(3)^(n-1) you have n+1

a1=-1/2

r=3

but with your formula

a1 = (-1/2)(3)^2 = -9/2

with the standard geometric formula for the nth term

a1 =-1/2

a2 = -3/2

a3 = -9/2

a4 =-27/2

....

Answer 2

a_n = a₁(r)^n-1

What is r in the given equation?