Evaluate: `int1/(sqrt(16-6x-x^2))\ dx`

Explanation

`I=int1/(sqrt(16-6x-x^2))\ dx`

`I=int1/(sqrt(-[x^2+6x-16]))\ dx`

`I=int1/(sqrt(-[x^2+6x-16+9-9]))\ dx`

`I=int1/(sqrt(-[(x-3)^2-25]))\ dx`

`I=int1/(sqrt(25-(x+3)^2])\ dx`

let `x+3=t`

`dx=dt`

So,

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