Answer
$f(30)=3$
$f(11)=2$
$f(2)=-1$
$f(-122)=-5$.
Work Step by Step
The given function is
$f(x)=\sqrt[3] {x-3}$
Plug $x=30$ into the function.
$f(30)=\sqrt[3] {30-3}$
Simplify.
$f(30)=\sqrt[3] {27}$
$f(30)=\sqrt[3] {3^3}$
$f(30)=3$
Plug $x=11$ into the function.
$f(11)=\sqrt[3] {11-3}$
Simplify.
$f(11)=\sqrt[3] {8}$
$f(11)=\sqrt[3] {2^3}$
$f(11)=2$
Plug $x=2$ into the function.
$f(2)=\sqrt[3] {2-3}$
Simplify.
$f(2)=\sqrt[3] {-1}$
$f(2)=\sqrt[3] {(-1)^3}$
$f(2)=-1$
Plug $x=-122$ into the function.
$f(-122)=\sqrt[3] {-122-3}$
Simplify.
$f(-122)=\sqrt[3] {-125}$
$f(-122)=\sqrt[3] {(-5)^3}$
$f(-122)=-5$.
