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How are you trying to enter such a complex number?
I know you can press 3 i 4 and get that complex number on the stack, but what are you pressing to create a complex number using a variable or a constant?
Give us a specific example of what keys you're pressing (or what equation you're trying) and that will help.
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I wanted to try Euler's equation:
e^(i(pi)) + 1 = 0
For the exponent if I enter "0 i 3.14" where I manually enter an estimate of pi, I'm OK
If I enter "0 i shift pi" I am left with pi in the real portion of the number with no imaginary component and who know what in rectangular form in the Y register above it. This is very perplexing.
So I tried storing pi in the "a" register and tried: "0 i RCL a" and I get the same kind of nonsensical result. It sure is frustrating.
Edited: 10 Oct 2007, 3:07 p.m.
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The reason is because you cannot build complex numbers from values in registers or constants in the manner you are trying.
You can see this in a program.
In program mode, press EQN to turn on equation mode and type:
RCL B then i then 2
Now leave program mode and singlestep that program line. You get a syntax error.
Try the approach shown in the next posting.
Edited: 10 Oct 2007, 4:07 p.m. after one or more responses were posted
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Gene,
Thanks for your thoughtful response even though it isn't what I wanted to hear! It's too bad a complex variable cannot be constructed from constants or a register  why should the calculator care where the number comes from?
Oh well, on to the next problem like world peace or some such thing.
Cheers,
Ike
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Try:
PI
i
*
e^x
1
+
With a reg:
i
RCL* P
e^x
1
+
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Egan,
I will try your steps when I get home for there is where I left my HP35s. I will certainly let you know the outcome unless someone has a 35s with them now and can try your procedure.
Thanks,
Ike
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Ike 
Egan Ford's previous response is correct. The reason for the seeminglyinconsistent behavior is that hitting the pi key terminates data entry and pushes pi onto the stack. A previouslyentered "i" then becomes a complete number, represented as "0i1" (0 + i1). Multiplying pi by "i" in either order produces the value you wanted.
I have made detailed suggestions to HP's calculator team for improving the complexnumber functionality, and will continue to follow up on them. Help may be on the way, if you're willing to wait a number of months.
 KS
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Karl,
Yes, Eagan is correct especially in the first solution. I had a bit more problem with the second but I'm not going to worry about it anymore. The bottom line is that now with the help from you folks I have something I can live with  thanks!
Now get those HP folks in line!
Cheers!
Ike
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For the 2nd:
1. Put a value in a register, e.g. A
2. Then type:
i
RCL* A i.e. RCL, then x (times), then A, aka recall arithmetic.
Or to make it easy:
i
RCL A
*
Both will build you a complex number from registers. For A+iB:
number
STO A
number
STO B
i
RCL* B
RCL+ A
OR
i
RCL B
*
RCL A
+
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Karl  I'm numb with this stuff. Having solved all complex problems with the 42s why did HP need to reinvent the wheel?
tm
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Quote:
Karl  I'm numb with this stuff. Having solved all complex problems with the 42s why did HP need to reinvent the wheel?
Two reasons:
1) Companies are ruled by marketing.
2) There is no such thing as one tool for every job.
Dave.
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Dave
You missed my point.
tm
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Quote:
You missed my point.
Ok, sorry, what was your point?
Dave.
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Hi, Trent 
Quote:
Having solved all complex problems with the 42s why did HP need to reinvent the wheel?
Well, I can't fully concur on that point. I have yet to see a calculator from any manufacturer having ideal complexnumber functionality, but certainly the HP42S is among the best. Its display of complex numbers is perfect, but the HP42S lacks the following:
 Direct, onestep entry of complex numbers in rectangular or polar form in either "mode" (as the HP35s has)
 A menu of complexnumber functions (as the HP28C/S has)
 Mixedmode display of complex numbers with mostreasonable result format (Simple and straightforward, but I've never seen it done  by HP or by TI or Casio in the models I've examined)
Details will follow, hopefully within a week. Here's a sample:
Userfriendly complex numbers
 KS
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In mathematics, the square of imaginary unit i is 1. If I enter the imaginary number 0i1 and then take the square of it (x^2), the HP 35s displays "INVALID DATA." The same happens when I enter any complex number and take the square of it using the x^2 key on the calculator.
If I enter the following, as shown in manual, p. 95:
1i1
ENTER
2 (positive 2 here)
y^x
The result is 0i2, since (1 + i)^2 = 1^2 + i + i + i^2 = 1 + 2i 1 = 0 + 2i
So, in one way, the 35s does compute i^2. But just using x^2 will not work. If I enter:
i
1
ENTER
2
y^x
I get the result as 1i0 (or 1 + 0i). I originally thought the 35s did not compute i^2 at all, but it does. As noted in the manual, you can y^x to compute powers of a complex number.
Cheers!
David Bailey
Edited: 11 Oct 2007, 1:51 a.m.
