In this problem i go this way>>>
let t=tanx and substitute in this problem but, i did not the "ln" in my final answer,,,,What can i do?????
I think it might be best to show us your working out so we can see if you slipped up somewhere in your algebra. This is more relevant if you are using a specific substitution rather than trying to solve it via brute-force or brain-storming before you try a specific solution.