# What is the domain of the function f(x) = sqrt{x^3 - 3x^2}?

$= \sqrt{{x}^{2} \cdot \left(x - 3\right)} = x \sqrt{x - 3}$
Now the $\left(x - 3\right)$ under the root must be non-negative, so the domain is restricted to $x \ge 3$ where $f \left(x\right) \ge 0$