Question

How do I find the domain of:

y=squareroot of x^3-3x^2 ?

Answer 1

I will assume that you meant to write
y = squareroot of (x^3-3x^2) and not
y = (squareroot of x^3) - 3x^2

Since you cannot take the square root of a negative number (unless you are dealing with imaginary numbers), the domain is wherever x^3 > 3x^2. Since x^2 is always positive, you can divide both sides by x^2 and keep the > sign in the same direction. This leaves you with x > 3