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LynzM Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-23-06 09:24 PM
Original message
Hey **aePrime**, you around??
And if so, how familiar are you with complex math of the form (z=x+iy)?
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aePrime Donating Member (676 posts) Send PM | Profile | Ignore Mon Oct-23-06 09:30 PM
Response to Original message
1. !!! I'm being called out!
I know a lot of math, but haven't done much with complex numbers in many years, having very little need for them in my field. I may yet be able to figure something out though.
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LynzM Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-23-06 09:56 PM
Response to Reply #1
2. Ok, I'll throw this at you on the off chance...
Let me start with, I loathe proofs :) Which makes the first of these two loads of fun...

1.) Show that complex conjugate (CC(sin(iz)) = sin(CC(iz)) iff z=n*pi*i (n=0,+-1, +-2....) (sorry for the poor notation, I don't have any spiffy programs to clean it up with!) given that

sin(z) = (exp(iz) - exp(-iz))/2i

I can do a lot of algebra and get down to:

((1/exp(x)-exp(x))*(sin(-y)+sin(y)) = 0

but I don't know how that helps me, as the second part is always =0, so who cares what x is, which neither of those addresses the "iff z=n*pi*i" part, at all. *sigh*


The second one is maybe more straightforward, but I'm still stuck:

2.) Solve the equation cos(z) = sqrt(2) w/out using cos-1(z) = -ilog{z+i(1-z^2)^.5}

given cos(z) = (exp(iz)+exp(-iz))/2

again, lots of algebra winds me up with cos(x)*(exp(-y)+exp(y))= 2*sqrt(2)


Thanks for any help, thoughts, suggestions... I feel like I just got totally in over my head in this class, and a week ago I felt like I was doing okay. Eek. Anyone else is welcome to jump in, too, if you want! :hi:
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aePrime Donating Member (676 posts) Send PM | Profile | Ignore Mon Oct-23-06 10:18 PM
Response to Reply #2
3. I'm looking
but I think I'm out of my league. I've never done complex analysis. Maybe I should have -- it looks interesting.
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LynzM Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-23-06 10:20 PM
Response to Reply #3
4. It *is* interesting
There's a lot of neat stuff that we've talked about... check out the Reimann sphere, for a neat bit of brain-bending. If I survive this class, it'll be some miracle, though - I haven't had a math class in about 5 years.

I'll sell ya my textbook when I'm done, though... ;)
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aePrime Donating Member (676 posts) Send PM | Profile | Ignore Mon Oct-23-06 10:35 PM
Response to Reply #4
5. I keep thinking
"This just boils down to trig. I know trig!", but the pieces aren't falling for me. Sorry!

Maybe you can ask Commie Pinko Dirtbag. He's a smart guy.

But you've given me something else to learn. :)

Feel free to ask me about calculus, or linear algebra, or my real field, (theoretical and practical) computer science in the future. :)
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LynzM Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Oct-23-06 10:42 PM
Response to Reply #5
6. Yeah, there's a lot of trig to it...
Euler's formula comes up a LOT.

No worries, I think I can make it to office hours to talk to my prof tomorrow... thanks for looking at it, though! I'll call you out again next time I have calc or linear alg. or CS apps questions! :hi:
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