lxrandr software package provides LXDE monitor configuration tool, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install lxrandr
lxrandr is installed in your system.
Make ensure the lxrandr package were installed using the commands given below,
$ sudo dpkg-query -l | grep lxrandr *
You will get with lxrandr package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | X Window System software |
| Package | lxrandr |
| Version | 0.1.2-3 |
| Description | LXDE monitor configuration tool |
| Sub Section | x11 |