Respuesta :
Answer: The correct option is second.
Explanation:
The given function is,
[tex]f(x)=5(0.8)^x[/tex]
If we graph a function is f(x), then its coordinates is defined as (x,f(x)).
When the graph of f(x) is reflect across the x-axis, then the the x-coordinate remains the same and the sign of y-coordinate is changed. It means after reflecting across the x-axis,
[tex](x,y)\rightarrow(x,-y)[/tex]
The given given equation can be written as,
[tex]y=5(0.8)^x[/tex]
To find the equation of the graph after reflection across the x-axis multiply both sides by -1.
[tex]-y=-5(0.8)^x[/tex]
Because f(x)=y and g(x)=-y.
[tex]g(x)=-5(0.8)^x[/tex]
Therefore the second option is correct and the graph of both function is given below.

Answer:
B. g(x) = –5(0.8)^x
Step-by-step explanation:
We have the function, [tex]f(x) = 5(0.8)^x[/tex].
It is required to reflect the function about x-axis.
Now, as we know,
Reflection across x-axis will flip the graph of the function and the function [tex]f(x)[/tex] becomes [tex]-f(x)[/tex].
So, the reflection of [tex]f(x) = 5(0.8)^x[/tex] across x-axis will give the function [tex]f(x) = -5(0.8)^x[/tex]
So, we see that,
Option B i.e. [tex]g(x) = -5(0.8)^x[/tex] is correct.