Answer:
Option B
Step-by-step explanation:
I did the test and I got it right.
Answer: [tex]f(n)=2(-4)^{n-1}[/tex]
Step-by-step explanation:
The explicit formula for geometric series is given by :_
[tex]f(n)=ar^{n-1}[/tex]
, where r= common ratio.
a= first term.
The given geometric series : 2, −8, 32, −128, …
First term = 2
Common ratio = [tex]\dfrac{-8}{2}=-4[/tex]
Substitute the value of a and r in (1) , we get
[tex]f(n)=2(-4)^{n-1}[/tex]
Hence, the representation of the given geometric series using the explicit formula : [tex]f(n)=2(-4)^{n-1}[/tex]
