Answer
$f(n)=6n+17$
Work Step by Step
From the mapping diagram,
First term $a_{1}=23$ and
Fourth term $a_{4}=41$.
$a_{4}=a_{1}+3d$ where $d$ is the common difference.
$\implies d=\frac{a_{4}-a_{1}}{3}=\frac{41-23}{3}=6$
$f(n)=a_{1}+(n-1)d$
$=23+(n-1)6$
$=23+6n-6$
$=6n+17$
The function $f(n)=6n+17$ represents the arithmetic sequence.
