[Math] Finding complex solutions of an equation

complex numbers

How does one solve this equation. I would like to see the solution of this problem in steps.

$z\cdot\bar{z}=\left|3\cdot z \right|$

EDIT: Is it possible to solve this by converting to the form $z=a+b\cdot i$

What about the solution of this equation.

$z\cdot\bar{z}-z^{2}=1-i$

EDIT2:

$a^2+b^2-(a+b\cdot i)(a+b\cdot i) = 1 – i$
$a^2+b^2-a^2-ab\cdot i – ab\cdot i + b^2=1-i$
$2b^2-2ab\cdot i = 1-i$

And we keep in mind that two imaginary numbers are equal if their real and imaginary parts are the same.

$2b^2 = 1$ and $-2ab=-1$
So $b = \pm \frac{1}{\sqrt{2}}$
and $a=\frac{1}{2b}\Rightarrow a=\pm \frac{\sqrt{2}}{2}$.

Is this correct?

Best Answer

In steps:

  1. $z\cdot \bar z = |z|^2$;

  2. $|3\cdot z| = 3|z|$;

  3. $|z|^2 = 3|z|\Leftrightarrow |z| = 0\text{ or }|z| = 3\Leftrightarrow z = 0\text{ or }z = 3\mathrm e^{i\phi}$ for $\phi\in\mathbb R$.

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