4. Given
$$\begin{aligned}
& \mathrm { f } ( x ) = \mathrm { e } ^ { x } , \quad x \in \mathbb { R }
& \mathrm {~g} ( x ) = 3 \ln x , \quad x > 0 , x \in \mathbb { R }
\end{aligned}$$
- find an expression for \(\mathrm { gf } ( x )\), simplifying your answer.
- Show that there is only one real value of \(x\) for which \(\operatorname { gf } ( x ) = \operatorname { fg } ( x )\)