Draw the graph of `y = cos pix`.

Explanation

To draw the graph of the function \( y = \cos(\pi x) \), follow these steps:

### Step 1: Understand the Basic Graph of \( y = \cos(x) \)
The graph of \( y = \cos(x) \) is a wave-like function that oscillates between 1 and -1. The key points are:
- At \( x = 0 \), \( y = \cos(0) = 1 \)
- At \( x = \frac{\pi}{2} \), \( y = \cos\left(\frac{\pi}{2}\right) = 0 \)
- At \( x = \pi \), \( y = \cos(\pi) = -1 \)
- At \( x = \frac{3\pi}{2} \), \( y = \cos\left(\frac{3\pi}{2}\right) = 0 \)
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