Find the second order derivatives of the functions given.
`x.cos x`

Explanation

To find the second-order derivative of the function \( y = x \cos x \), we will follow these steps:

### Step 1: Differentiate the function to find the first derivative \( y' \).

Using the product rule, which states that if \( y = u \cdot v \), then \( y' = u'v + uv' \), we identify:
- \( u = x \) and \( v = \cos x \)

Now, we differentiate \( u \) and \( v \):
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