Sally graphs the geometric sequence an = 2(3)n - 1 on a coordinate plane where she plots an on the y-axis and n on the x-axis. This graph is the same as the graph of which type of function?

Question

Sally graphs the geometric sequence an = 2(3)n - 1 on a coordinate plane where she plots an on the y-axis and n on the x-axis. This graph is the same as the graph of which type of function? 
A) cubic 
B) linear <my answer 
C) quadratic 
D) exponential

Reiny · Accepted Answer

I have a suspicion that your equation looked something like
a_n = 2(3^n) - 1

or else , why wouldn't they have written it as
a_n = 6n - 1 , which would indeed be linear,

If it is as I suspected, it would be exponential.