To apply Theorem 2.3 to show that the function \( g(x) = \pi + 0.5 \sin\left(\frac{x}{2}\right) \) has a unique fixed point on the interval \( [0, 2\pi] \), we will verify the conditions for uniqueness and then use fixed-point iteration to find the fixed point.
### Step 1: Establish Fixed Point
A fixed point of the function \( g \) occurs when \( g(x) = x \). This requires solving the equation:
\[
x = \pi + 0.5