The number of complex numbers z satisfying $\bar{z}=i z^2$ is

The number of complex numbers z satisfying $\bar{z}=i z^2$ is
  1. 3
  2. 4
  3. 2
  4. 5

Solution

Given equation is $\overline{\mathrm{Z}}=\mathrm{iz}^2...(i)$ Let $\mathrm{Z}=\mathrm{x}+\mathrm{iy} \Rightarrow \overline{\mathrm{Z}}=\mathrm{x}-\mathrm{iy}$ Now, from equation (i) $ \begin{aligned} & x-i y=(x+i y)^2 \\ & x-i y=i\left(x^2-y^2+2 i x y\right) \\ & x-i y=i x^2-i y^2-2 x y \\ & \Rightarrow 2+2 x y=0 \text { and } y=y^2-x^2 \end{aligned} $ On solving get $(0,0)(0,1)\left(\frac{-\sqrt{3}}{2}, \frac{-1}{2}\right)\left(\frac{\sqrt{3}}{2}, \frac{-1}{2}\right)$ are four solutions

Asked in: AP EAMCET 2022 (06 Jul Shift 1)

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