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general >> complex analysis >> History of complex numbers
(Message started by: Mickey1 on Feb 10th, 2011, 7:56am)

Title: History of complex numbers
Post by Mickey1 on Feb 10th, 2011, 7:56am
Does anyone know how people understood
for instance

exp(ix) = cos(x)+i sin(x)  from the beginning (=in the 18 hundreds).

Was it by looking at the power series
of 1+ix+(ix)^2/2 ... , and the corresponding series for cos(x) +  i sin(x)?

or did that come later?

Title: Re: History of complex numbers
Post by towr on Feb 10th, 2011, 9:08am
I don't really know much about it, but http://en.wikipedia.org/wiki/Complex_numbers#History treats a bit of the history of complex numbers. From what it says it seems like Euler started from the complex power series, and then found Euler's formula.

Title: Re: History of complex numbers
Post by Mickey1 on Feb 14th, 2011, 12:15am
Thank you for that.

I note the formular came up 100 years earlier than I thougth.


Title: Re: History of complex numbers
Post by fizyka on Dec 30th, 2011, 3:27pm
It's funny they just came up something and then much later they use it in somefields like electronics etc.



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