#### Answer

$$\sin \left(x\right)$$

#### Work Step by Step

Simplifying the expression using the sum and difference formulas, we find:
$$\sin \left(x+2\pi \right) \\ \cos \left(x\right)\sin \left(2\pi \right)+\cos \left(2\pi \right)\sin \left(x\right) \\ \sin \left(x\right)$$