\begin{tikzpicture}

	\draw[->] (-2,0) -- (2,0) node[right] {x};
	\draw[->] (0,-2) -- (0,2) node[above] {y};
	\draw[scale=0.5,domain=0:3,smooth,variable=\x,blue] plot ({\x},{\x});
	\draw[scale=0.5,domain=-3:0,smooth,variable=\x,blue] plot ({\x},{exp(\x)-1});

\end{tikzpicture}