Evaluate: (i) `int1/(x\ sqrt(x^4-1))\ dx` (ii) `intsqrt(e^x-1)\ dx`

Explanation

Let's solve the integrals step by step.

### (i) Evaluate the integral \( \int \frac{1}{x \sqrt{x^4 - 1}} \, dx \)

**Step 1: Substitution**
We will use the substitution \( x^2 = \sec \theta \). Therefore, \( dx = \frac{1}{2\sqrt{\sec \theta}} \sec \theta \tan \theta \, d\theta \).

**Step 2: Transform the integral**
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