Integrate the following
`1/(sqrt(x^(2)+a^(2)))`

Explanation

To integrate the function \( \frac{1}{\sqrt{x^2 + a^2}} \), we can follow these steps:

### Step 1: Set up the integral
Let \( I = \int \frac{1}{\sqrt{x^2 + a^2}} \, dx \).

### Step 2: Use a trigonometric substitution
We will use the substitution \( x = a \tan(\theta) \). This implies that \( dx = a \sec^2(\theta) \, d\theta \).

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