Old Yahoo passwords

For what reason ?

If they are your passwords, from the book or paper where you wrote them down to remember them

Also from Yahoo support. Just log in under the name used and ask them to send you a new one after you verify who you are.

There is no way to obtain previous passwords that you may have used unless you wrote them down someplace. If you have forgotten your password, you can use the forgotten password link to get a new one generated.