How do I find out my Mac OSx admin password without changing it?
OS X does not store a plain-text copy of your administrator password. This makes it impossible to have the computer show you the existing password.

OS X can only test if an attempted password is the administrator password.

OS X has no way to show you the original. The original is immediately thrown away when the password is set; only a hash of the password is kept.

Why? Hashed Passwords

Passwords are stored as mathematically derived hashes of the original. This hash makes it possible to determine if an attempted password matches the real password, but it also makes it impossible to determine the real password.