If $z=x+i y, x y \neq 0$, satisfies the equation $z^2+i \bar{z}=0$, then $\left|z^2\right|$ is equal to :
Solution
<p>$$\begin{aligned}
& z^2=-i \bar{z} \\
& \left|z^2\right|=|i \bar{z}| \\
& \left|z^2\right|=|z| \\
& |z|^2-|z|=0 \\
& |z|(|z|-1)=0 \\
& |z|=0 \text { (not acceptable) } \\
& \therefore|z|=1 \\
& \therefore|z|^2=1
\end{aligned}$$</p>
About this question
Subject: Mathematics · Chapter: Complex Numbers and Quadratic Equations · Topic: Complex Numbers and Argand Plane
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