Is the statement true or false: numbers in the domain of a radical function will always be nonnegative?

May 7, 2017

False

Explanation:

Radical functions include cube (and higher odd degree) roots, which are defined for any radicand.

The function $f \left(x\right) = {x}^{3}$ is one to one from $\left(- \infty , \infty\right)$ onto $\left(- \infty , \infty\right)$, with inverse ${f}^{- 1} \left(x\right) = \sqrt[3]{x}$ (understood as the real cube root).