∫(1 / x) log x dx =

1) log_e (1 – log_e x) + c

2) log_e (log_e ex – 1) + c

3) log (log x – 1) + c

4) log_e (log_e x + x) + c

5) log (log x) + c

Solution: (5) log (log x) + c

Take log x = t

(1 / x) dx = dt

∫dt / t = log t + c

t = log (log x) + c