Evaluate: f(x)=sqrt(x-10)

Expression: $f\left( x \right)=\sqrt{ x-10 }$

Separate the function into parts to determine the domain of each part

$\begin{array} { l }\sqrt{ x-10 },\\x-10\end{array}$

The domain of an even root function are all values of $x$ for which the radicand is positive or $0$

$\begin{array} { l }x \geq 10,\\x-10\end{array}$

The domain of a linear function is the set of all real numbers

$\begin{array} { l }x \geq 10,\\x \in ℝ\end{array}$

Find the intersection

$\begin{align*}&x \in \left[ 10, +\infty\right\rangle \\&\begin{array} { l }x \geq 10\end{array}\end{align*}$