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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 single-step 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 seemingly-inconsistent behavior is that hitting the pi key terminates data entry and pushes pi onto the stack. A previously-entered "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 complex-number 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 complex-number functionality, but certainly the HP-42S is among the best. Its display of complex numbers is perfect, but the HP-42S lacks the following:
- Direct, one-step entry of complex numbers in rectangular or polar form in either "mode" (as the HP-35s has)
- A menu of complex-number functions (as the HP-28C/S has)
- Mixed-mode display of complex numbers with most-reasonable 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:
User-friendly 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. 9-5:
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.
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