Path: utzoo!attcan!uunet!meaddata!mead!johnt@uccba.uc.edu
From: mead!johnt@uccba.uc.edu (John Townsend)
Newsgroups: comp.sys.handhelds
Subject: Re: Unit Problems Solved! (Was:Re: Units Problems...
Message-ID: <1473@meaddata.meaddata.com>
Date: 26 Sep 90 16:36:47 GMT
References: <2237@charon.cwi.nl> <9682@ccncsu.ColoState.EDU> <9700@ccncsu.ColoState.EDU>
Sender: usenet@meaddata.com
Reply-To: mead!johnt@uccba.uc.edu (John Townsend)
Organization: Mead Data Central, Dayton OH
Lines: 28


In article <9700@ccncsu.ColoState.EDU>,
jn190068@longs.LANCE.ColoState.EDU (Jay Lewis Nestle) writes:
|> 
|> 	Thanks to all of the 48SX gurus out there!!! 
|> I do see the light now.  The notation seemed to just
|> throw me off, sorry for rehashing an old topic.  

This reminds me of when I first got my HP-28C when I was in college.  The first
thing I did with it was "acid-test" it by calculating the cube root of -27.
Every sixth-grader knows that the answer to this is simply -3, but most
calculators (including every TI I've ever seen) gag on it.  Up to that time,
the only calculator I'd seen give me a correct answer was a Sharp EL506-P that
I'd gotten for about $10.  Well, my $200 28C coughed out "(1.5,2.59807621135)".
"Bug!!!", I screamed.  Fortunately, before I could send any hate mail to HP,
a friend of mine who was taking Complex Variables at the time reminded me that
I was actually solving a cubic equation, which always has THREE correct answers
in the complex number domain.  Turns out that the 28C returns the first of
these (going around the complex plane counterclockwise from the X axis).  The
other two solutions are (-3,0) and (1.5,-2.59807621135).  The 28C will cube all
of these back into -27.  That sure raised by opinion of HP in a hurry!


--
     John Townsend                        Internet:   mead!johnt@uccba.uc.edu
 c/o Mead Data Central                    UUCP:       ...!uccba!mead!johnt
     P.O. Box 933                         Telephone:  (513) 865-7250 
  Dayton, Ohio, 45401