Step 1: Understand the problem.
The given expression is \( \sqrt{2} + \sqrt{2} + 2 \cos 4\theta \). First, simplify the terms that involve constants. We have \( \sqrt{2} + \sqrt{2} = 2\sqrt{2} \).
Step 2: Use trigonometric identities.
Now, consider the trigonometric term \( 2 \cos 4\theta \). Since \( 4\theta \) can be simplified using angle identities, the equation simplifies to:
\[
2\sqrt{2} \cos \theta
\]
Step 3: Conclusion.
Thus, the simplified result is \( 2 \cos \theta \).