`(1)/(sqrt(9-25x^(2)))`

Explanation

`int(1)/(sqrt(9-25x^(2)))dx=(1)/(5)int(1)/(sqrt(((3)/(5))^(2)-x^(2)))dx`
`=(1)/(5)sin^(-1)((x)/(3//5))+c`
`=(1)/(5)sin^(-1)((5x)/(3))+c`