Complex numbers powers and logs

Liquidxlax
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Homework Statement



(-e)^iπ answer is -e^-π2

not sure how to describe this one, but i need to find the roots.

Homework Equations



(r^n)e^(itheta)n = (r^n)cos(thetan) + isin(thetan) n is an element of the reals

The Attempt at a Solution




i'm not sure what to do with this, it is the most weird question on the page. it seems circular to me.
 
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I'm not sure exactly what you are asking here. Here is my attempt at some help.

When dealing with complex numbers, we can use De Moivre's formula to find roots.

\alpha={r}{e}^{i\theta}

\alpha^{\frac{p}{q}}={r}^{\frac{p}{q}}{exp(ip({\theta}+2n{\pi})/q)}

Example: Find the roots of

i^{\frac{1}{3}}

Using:

i=e^{\frac{i{\pi}}{2}}

And the above equation gives the roots as:

e^{\frac{i{\pi}}{6}}

e^{\frac{5i{\pi}}{6}}

e^{\frac{9i{\pi}}{6}}

I hope that helps.
 
not really because applying that i still don't get the right answer. I've done many of these types of questions, its just that this one is really weird.

like if i ln and then put it to the e, it is the same thing...
 
You want to find the roots of a function, right? For which function do you want to find the roots?
 
CalcYouLater said:
You want to find the roots of a function, right? For which function do you want to find the roots?

-e^ipi i know the answer is -e^(-ipi^2)
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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