Draw the graph of `[y] = cos x, x in [0, 2pi],` where `[*]` denotes the greatest integer function.

Explanation

To draw the graph of \( y = [\cos x] \) for \( x \) in the interval \([0, 2\pi]\), where \([\cdot]\) denotes the greatest integer function, we will follow these steps:

### Step 1: Understand the function \( \cos x \)
The cosine function oscillates between -1 and 1. We need to evaluate \( \cos x \) at key points in the interval \([0, 2\pi]\).

### Step 2: Calculate \( \cos x \) at key points
- \( \cos(0) = 1 \)
- \( \cos\left(\frac{\pi}{3}\right) = \frac{1}{2} \)
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