cosine: if z = 1/z = 2 cos 3°, then show that z + 1/z =....
- Thread starter malick
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pka
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Re: cosine
Assuming z is a complex variable, the way it is, the statement is not true.
Post Script.
I think that I know this as a standard problem in most complex variables texts.
If \(\displaystyle \L
\left| z \right| = 1\) then \(\displaystyle \L
z + \frac{1}{z} = 2\cos (\phi )\quad \& \quad z^n + \frac{1}{{z^n }} = 2\cos (n\phi )\)
Please review this post. There is something wrong.malick said:
Assuming z is a complex variable, the way it is, the statement is not true.
Post Script.
I think that I know this as a standard problem in most complex variables texts.
If \(\displaystyle \L
\left| z \right| = 1\) then \(\displaystyle \L
z + \frac{1}{z} = 2\cos (\phi )\quad \& \quad z^n + \frac{1}{{z^n }} = 2\cos (n\phi )\)