Mac Keyboard Shortcut To Mirror Displays

You have a second display attached to your Mac and since 2007 the Mirror Displays function key has been removed. Sou you would need to go to System Preferences then Displays to change the Arrangement. However there is a little known keyboard shortcut to switch from extended desktop to mirror displays and that is the combination of the keys Command and F1. Trigger those keys with a second display attached and they are mirrored.