Step 1: Find the maximum and minimum values of the function.
To find the maximum and minimum values, use the derivative of \( f(x) = 2 \sin x + \sin 2x \) to determine the critical points.
Step 2: Conclusion.
Thus, the difference between the maximum and minimum values of \( f(x) \) is \( \sqrt{5} \).
Final Answer:
\[
\boxed{\sqrt{5}}
\]