Determine the domain of F(x): = Square root{[(x2-2x+5)/(x3-1)]} and carefully show that F is continuous on its domain.
What you're square rooting has to be greater than or equal to zero: $\displaystyle \frac{x^2-2x+5}{x^3-1} \geq 0$. And you require the restriction $\displaystyle x^3 - 1 \neq 0$.