Chapter 4 - Section 4.2 - Exponential Functions - 4.2 Exercises - Page 412: 108

$f(x)=5^x$

First, we have to find the function, by calculating the base, $a$. If the function contains this point (3,125), then $f(3)=125$, this means: $a^3=125$ We take the cube root of both sides: $a=5$ Therefore, with $5$, the function is $f(x)=5^x$.