Integrate the functions`sqrt(1-4x-x^2)`

Explanation

To integrate the function \( \sqrt{1 - 4x - x^2} \), we can follow these steps:

### Step 1: Rewrite the Integral
Let \( I = \int \sqrt{1 - 4x - x^2} \, dx \).

### Step 2: Factor Out the Negative Sign
We can rewrite the expression inside the square root by factoring out a negative sign:
\[
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