Evaluate the following integral:`int_0^1("log"(1+x))/(1+x^2)dx`

Explanation

To evaluate the integral \( I = \int_0^1 \frac{\log(1+x)}{1+x^2} \, dx \), we will follow a systematic approach.

### Step 1: Substitution
We start by making the substitution \( x = \tan \theta \). This gives us:
\[ dx = \sec^2 \theta \, d\theta \]
When \( x = 0 \), \( \theta = 0 \) and when \( x = 1 \), \( \theta = \frac{\pi}{4} \).
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