Evaluate : `int_(1)^(2) (cos (log x))/(x) dx `

Explanation

To evaluate the integral \( I = \int_{1}^{2} \frac{\cos(\log x)}{x} \, dx \), we will use substitution.

### Step-by-Step Solution:

1. **Substitution**: Let \( t = \log x \). Then, we differentiate both sides:
\[ dt = \frac{1}{x} \, dx \quad \Rightarrow \quad dx = x \, dt = e^t \, dt \]
...