# What is the domain of (2x^2+x-1)/(x^3-9x)?

The domain is all the real values except those who nullify ${x}^{3} - 9 x$
So we have ${x}^{3} - 9 x = 0 \implies x \left({x}^{2} - 9\right) = 0 \implies x = 0 , x = 3 , x = - 3$
So the domain is $R - \left\{0 , - 3 , 3\right\}$ where R is the set of real numbers