Evaluate `int(3x^(2)"tan"(1)/(x)-x"sec"^(2)(1)/(x))dx`.

Explanation

To evaluate the integral \( I = \int \left( 3x^2 \tan\left(\frac{1}{x}\right) - x \sec^2\left(\frac{1}{x}\right) \right) dx \), we can follow these steps:

### Step 1: Split the Integral
We can separate the integral into two parts:
\[ I = \int 3x^2 \tan\left(\frac{1}{x}\right) dx - \int x \sec^2\left(\frac{1}{x}\right) dx \]

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