Question

Evaluate`int (1)/(x(3+log x))dx` 

Answer 1

`int (1)/(x(3+log x))dx`  

Put  `3+log x=t` 

`1/x dx=dt` 

∴ `int dt/t+c`

`int dt/(3 +t)`

= `log [3 + t] + c

= `log (3+log x)+c`