We take the function as a sequence
Term 1 ⇒ 5
Term 2 ⇒ 4
Term 3 ⇒ 3.2
Between terms, there is a common ratio of ⁴/₅
We get it from here:
Term 2 / Term 1 = [tex] \frac{4}{5} [/tex]
Term 3 / Term 2 = [tex] \frac{3.2}{4} [/tex] = [tex] \frac{4}{5} [/tex]
When a sequence has a common ratio between term, the sequence is a Geometric Sequence
[tex]n_{th}term=ar^{n-1}[/tex]
Where [tex]a[/tex] is the first term, [tex]r[/tex] is the common ratio, and [tex]n[/tex] is the term number
We have: [tex]a=5[/tex] and [tex]r= \frac{4}{5} [/tex]
The formula for the function is
[tex]f(x)=5( \frac{4}{5})^{x-1} [/tex]
