Answer
$f(x)=x^3-1$
Domain: $R$
Work Step by Step
A function $y=f(x)$ so that $y$ is 1 less than $x^3$ is:
$f(x)=x^3-1$
We graph the function starting from the parent function $p(x)=x^3$ which we shift one unit down.
The domain of the function is the set of all real numbers $R$.