On Wed, 15 Feb 2012 at 06:15AM +0000, Dr. David Kirkby wrote:
> What is sqrt(i), and why?

As for sqrt(i), if you represent it as exp(i*pi/2), there are two
numbers z that satisfy z^2 = i, namely exp(i*pi/4) and exp(i*5*pi/4).
Look up the polar form of complex numbers.

As for why: well, why should non-integer powers be reserved for real
numbers? If I can find a number w so that w^2 = z, who wouldn't call
that the/a square root root of z? Math would make no sense if we
arbitrarily decided to not do things in the complex numbers even though
they are simple and easy to imagine.

> Put me out of my misery.

I should hope that learning the polar form of complex numbers doesn't
cause anyone misery!

Dan

--
---  Dan Drake
-----  http://mathsci.kaist.ac.kr/~drake
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