1. **State the problem:**
We need to sketch the graph of the function $$y = \cos\left(\frac{x}{2}\right) + 1$$ including two full periods and correct axis markings.
2. **Formula and important rules:**
The general cosine function is $$y = A \cos(Bx - C) + D$$ where:
- Amplitude = $$|A|$$
- Period = $$\frac{2\pi}{|B|}$$
- Midline = $$y = D$$
- Phase shift = $$\frac{C}{B}$$
For our function, $$A = 1$$, $$B = \frac{1}{2}$$, $$C = 0$$, and $$D = 1$$.
3. **Calculate the period:**
$$\text{Period} = \frac{2\pi}{|B|} = \frac{2\pi}{\frac{1}{2}} = 4\pi$$
4. **Graph characteristics:**
- Amplitude = 1
- Midline = $$y = 1$$
- Period = $$4\pi$$
- Starts at maximum when $$x=0$$ because $$\cos(0) = 1$$, so $$y = 1 + 1 = 2$$
- Minimum at $$x = 2\pi$$ because $$\cos\left(\frac{2\pi}{2}\right) = \cos(\pi) = -1$$, so $$y = -1 + 1 = 0$$
5. **Sketch two full periods:**
- One full period spans $$4\pi$$, so two full periods span $$8\pi$$.
- Mark x-axis at $$0, 2\pi, 4\pi, 6\pi, 8\pi$$.
- Mark y-axis with midline at 1, maximum at 2, minimum at 0.
6. **Summary:**
The graph oscillates between 0 and 2, centered at 1, with period $$4\pi$$, starting at maximum at $$x=0$$, minimum at $$x=2\pi$$, maximum at $$x=4\pi$$, and repeats.
**Final answer:** The function $$y = \cos\left(\frac{x}{2}\right) + 1$$ has amplitude 1, midline $$y=1$$, period $$4\pi$$, and starts at maximum at $$x=0$$.
Cosine Graph Ce5837
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