A DFA for recognizing comments
There is no initial state, so there's no automaton. I suppose $1$ is the initial state.
From state 4 you can still read several times the symbol $*$ and accept the comment. For example, the coment /*hello*/ is being accepted, but the comment /*hello**/ is not. So you need $\delta(4,*)=4$.
Also, you need more transitions for the automaton to be a DFA. Remember that a DFA has a defined transition for all symbols from all states.

For example, you need transitions from $4$ with other symbols ($\delta(4,x)=3$ for $x\in\Sigma\smallsetminus\{*,/\}$).
The same goes for $1$ and $2$, but I leave that as an exercise ;-)