## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

Recall: a) A function is said to be odd, when every number $x$ in its domain, the number $-x$ is also in the domain such that $f(-x)=-f(x)$ b) A function is said to be even, when every number $x$ in its domain, the number $-x$ is also in the domain such that $f(-x)=f(x)$ It can be noticed that the given function $f(x)=\sqrt x$ has a domain of $(0, \infty)$. Note that for a positve real number $x$, the function is not defined for $-x$. Therefore, the function $f(x)$ is neither even nor odd.