Answer
$0\cup [3,\infty)$
Work Step by Step
The equation according to the text: $x^3-3x^2\geq0\\x^2(x-3)\geq0$
The zeros: $x=0$ or $x-3=0\\x=3$.
Then, according to the table (where I used the zeros ($x=0,3$) to divide the number line into different parts), the solution set: $0\cup [3,\infty)$ because the function is non-negative in this interval.
