Answer
$\left[ \dfrac{7}{2},\infty \right)$
Work Step by Step
The radicand of the given function, $
f(x)=\sqrt{2x-7}
,$ can only be a nonnegative number. Hence,
\begin{array}{l}\require{cancel}
2x-7\ge0
\\\\
2x\ge7
\\\\
x\ge\dfrac{7}{2}
.\end{array}
Hence, the domain is $
\left[ \dfrac{7}{2},\infty \right)
.$