All complex # satisfying the equation

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The discussion centers on solving the equation $i^z = 2$ using logarithmic properties. The principal logarithm leads to the solution $z = \frac{-2i\ln 2}{\pi}$. The general solution is expressed as $z = -i \frac{\ln 2}{\frac{\pi}{2} + 2k\pi}$, where $k$ is an integer. However, practical evaluations using Mathematica confirm that only $k = 0$ yields the solution $2$, aligning with the principal value of $\log i$.

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$i^z = 2$

Take the principal log so $\theta\in (-\pi, \pi)$
$$
z\log i = \ln 2\Leftrightarrow z\log |i| + zi\frac{\pi}{2} = \ln 2\Leftrightarrow z = \frac{-2i\ln 2}{\pi}.
$$

This is the only solution correct?
 
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dwsmith said:
$i^z = 2$

Take the principal log so $\theta\in (-\pi, \pi)$
$$
z\log i = \ln 2\Leftrightarrow z\log |i| + zi\frac{\pi}{2} = \ln 2\Leftrightarrow z = \frac{-2i\ln 2}{\pi}.
$$

This is the only solution correct?

The general solution of the equation $i^{z}=2$ is...

$\displaystyle z=-i\ \frac{\ln 2}{\frac{\pi}{2}+2 k \pi}$ (1)

Kind regards

$\chi$ $\sigma$
 
chisigma said:
The general solution of the equation $i^{z}=2$ is...

$\displaystyle z=-i\ \frac{\ln 2}{\frac{\pi}{2}+2 k \pi}$ (1)

Kind regards

$\chi$ $\sigma$

I thought that at first but if you use Mathematica and try values for k, no other value yields 2 except k = 0.
 
dwsmith said:
I thought that at first but if you use Mathematica and try values for k, no other value yields 2 except k = 0.
$k=0$ corresponds to the principal value of $\log i$, which is what the question asks for.
 

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