Question

A sequence has a ratio of 4. When n = 1, the value of the function is 16. Which function models the sequence?

A: f(n)=4x4n

B:f(n)=4n+2

C:f(n)=fn+8

D:f(n)=2x4n

Answer 1

Answer:

A. $f(n)=4(4)^{n}$

Step-by-step explanation:

The geometric sequence has the form:

$f(n)=ar^{n-1}$

where r=4 is the common ratio and $a=16$ is the first term.

When we plug in these values we obtain:

$f(n)=16(4)^{n-1}$

We can use properties of exponents to simplify further to get:

$f(n)=16\frac{(4)^{n}}{4^1}$

This gives us:

$f(n)=4(4)^{n}$

The correct answer is A.