Integrate the functions
`sqrt(1+3x-x^2)`

Explanation

To integrate the function \( \sqrt{1 + 3x - x^2} \), we will follow these steps:

### Step 1: Rewrite the expression under the square root
We start with the integral:
\[ I = \int \sqrt{1 + 3x - x^2} \, dx \]
First, we rearrange the expression inside the square root:
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