Question

Look at the graph.

Which function can be used to represent the graphed geometric sequence?

answer choices:

a) f(x)=80(1/4)^x-1

b) f(x)=320(1/4)^x-1

c) f(x)=80(4)^x-1

d) f(x)=320(4)x-1

Answer 1

its A on endgenuity

Explanation:

Answer 2

`f(x) =80 \cdot \: {( (1)/(4) )}^(x - 1)`

Explanation:

Fro the graph, the first three terms of the sequence are 80,20,5,...

This is a geometric sequence with first term

`f(1)= 80`

The common ratio is

`r = (20)/(80) = (5)/(20) = (1)/(4)`

The function is given by

`f(x) = f(1) \cdot \: {r}^(x - 1)`

We substitute the values we got from the graph into this formula to get:

`f(x) =80 \cdot \: {( (1)/(4) )}^(x - 1)`

The correct answer is A