Two Monitors (one Beamer) with diverent resolution

You can edit the xorg.conf. Or use xrandr.

> xrandr --output VGA1 --auto
> xrandr --output VGA2 --auto --right-of VGA1

You can replase --auto with --mode 1920x1080 for a fixed resolution.

Replace VGA1 and VGA2 with the names of Devices you use (xrandr can help to name them) and want to configure.

Usually any configuration done by this way should be still available after a restart. If not put this commands into a start-script.

By default the the second Screen is fixed for all workspaces. To change this type the following command.

gsettings set org.gnome.shell.overrides workspaces-only-on-primary false