Re: TI-85 and log(-4)


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Re: TI-85 and log(-4)



anybody know where euler got his formula, and what use it has?  I
vaguely remember using it in diff e q, but I can't remember why...

Jesse.Samuels@asu.edu

>Date: Fri, 25 Jul 1997 04:26:16 -0700
>From: "Jason T. Selkowitz" <selkowtz@U.WASHINGTON.EDU>
>Subject: Re: TI-85 and log(-4)
>To: CALC-TI@LISTS.PPP.TI.COM
>
>On Thu, 24 Jul 1997 18:56:52 GMT, David Socher wrote to Calc-TI:
>>
>> My algebra instructor had everyone punch the log of a negative number
>> into their calculator to demonstrate that this could not be done.
>
>What can and can't be done always depends on what you're trying to do
it
>with, as you saw...
>
>> Everyone got an error message except me and my TI-85.  I got
something
>> that looks like a complex number.
>
>Bingo!  This is what you got, assuming modes of RectC and Fix 4:
>
> (Fake TI-85 Screen)
>|--------------------|
>|log -4              |
>|      (.6021,1.3644)|  <--- This is the "rectangular" format for a
>|                    |       complex number.  The first number is the
>|                    |       real part, and the second number is the
>|                    |       imaginary part, where i=sqrt(-1).
>|                    |       Anytime you see this, until you take
>|                    |       advanced algebra, analysis, pre-calculus,
>|                    |       or whatever they call it in your school,
>|--------------------|       your classmates are getting error
messages.
>
>> The manual doesn't to cover it.
>
>See pages 11-2 through 11-4 regarding complex numbers, their format,
and
>the functions and commands for complex math.
>
>Hope this helps!
>
>
>Jason T. Selkowitz
>
>
>*************************Jason T. Selkowitz***************************
>* 16532 NE 36th Ct. LL202  * mailto:selkowtz@u.washington.edu        *
>* Redmond, WA  98052-6364  * http://weber.u.washington.edu/~selkowtz *
>**********************************************************************


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