B737 fail passive or operational?
 

Hey guys, how can understand if an airplane is fail passive or operational?
If it's fail operational airplane, with one engine inop, we can still auto land but what is the best way to know the plane's specification?

The simplest way is to check if you have a C/R button next to ENG and SYS buttons for the lower DU control... However your rudder servo may be deactivated if your operator chose to on otherwise fail operational capable airframes. Are you trained for fail operational ops, do your manuals mention it, is your company certified? If in doubt - ask!