Evaluate: `intlog(1+x^2)\ dx`

Explanation

To evaluate the integral \( I = \int \log(1 + x^2) \, dx \), we will use the method of integration by parts.

### Step-by-step Solution:

1. **Identify the functions for integration by parts**:
We will choose:
- \( u = \log(1 + x^2) \) (the logarithmic function)
- \( dv = dx \) (the differential of \( x \))
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