From: utzoo!decvax!harpo!ihnp4!ixn5c!inuxc!pur-ee!uiucdcs!becker
Newsgroups: net.math
Title: = .9999 . . . ? - (nf)
Article-I.D.: uiucdcs.1374
Posted: Tue Jan 25 00:27:03 1983
Received: Thu Jan 27 20:27:03 1983

#N:uiucdcs:28200002:000:748
uiucdcs!becker    Jan 24 23:41:00 1983

my room-mate and i got in an argument over this:

 i said 
          1 = .999999 . . . .
 
and gave a couple of proofs 
    1:    1/9 = .1111 . . . .
          9 * (1/9) = 9 * (.1111 . . . .)
          9/9 = .9999 . . . . 
          1 = .9999 . . . .     qed
 
    2:    10 * (.9999 . . . .) = 9.9999 . . . .
          10 * (.9999 . . . .) - 1 * (.9999 . . . .) 
                  = (9.9999 . . . .) - (.9999 . . . .) = 9
       so 9 * (.9999 . . . .) = 9
          (.9999 . . . .) = 1    qed
 
these may be no news to you.  however, edward did not believe them.  anyone
out there have a good convincing proof he might believe?  i wouldn't want to
say that money was bet on this question, but . . .
 
                thanks,
                 craig