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Here's a silly roots question that has my congested mind temporarily stumped:
Let z = 1 + \sqrt{2}. Find the five distinct fifth roots of z.
Thanks in advance for helping me relieve the pressure.
loandbehold
Nov24-04, 10:24 AM
Some of the roots are going to be complex, so the way I would tackle the problem is to rewrite your number in the form:
z=(1+\sqrt{2}){\rm e}^{2\pi ni},
where n=0,1,2,.... Then taking the fifth root gives:
z^{1/5}=(1+\sqrt{2})^{1/5} {\rm e}^{2\pi ni/5},
which you can write in the form:
z^{1/5}=(1+\sqrt{2})^{1/5} \left \{ \cos \left ( \frac{2\pi n}{5} \right) +i \sin \left( \frac{2\pi n}{5} \right) \right \}.
Evaluating this for different n, should give 5 distinct roots.
thank you very much for the insight...I now proceed to kick myself for not seeing it on my own {sound of kicking}
Thanks!
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