Answer
\[{{f}^{-1}}\left( 1 \right)=3\]
Work Step by Step
The value of the given function can be obtained using the definition of functions and the value of $f$ at the required point.
Let us consider, ${{f}^{-1}}\left( 1 \right)=x$ , then $f\left( x \right)=1$.
Since the value of $f\left( x \right)=2x-5$ , thus we have
$\begin{align}
& 2x-5=1 \\
& 2x=6 \\
& x=3
\end{align}$
Thus, ${{f}^{-1}}\left( 1 \right)=x=3$.
