Evaluate: `intx/((x^2+4)sqrt(x^2+9))dx`

Explanation

Let,

`x^2+9=t^2`

`x^2+4=t^2-5`


`2xdx=2tdt`


`xdx=tdt`


`=intx/((x^2+4)sqrt(x^2+9))dx`


`=int (tdt)/((t^2-5)t)`


`=int (dt)/((t^2-5))`


...