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← JEE Main 2022 · 27 Jul · Shift 1
MathematicsInteger+4 / -1Question 30 of 90

JEE Main 2022 · 27 Jul · Shift 1, Mathematics question 30

Let S={z∈C:z2+zˉ=0}S=\left\{z\in\mathbf C:z^2+\bar z=0\right\}. Then ∑z∈S(Re⁡(z)+Im⁡(z))\displaystyle\sum_{z\in S}\left(\operatorname{Re}(z)+\operatorname{Im}(z)\right) is equal to ______.

Answer and worked solution

Official answer: 0

Real and imaginary parts. x2−y2+x=0x^2-y^2+x=0 and y(2x−1)=0y(2x-1)=0.

Solutions. z=0,−1,12±32iz=0,-1,\frac12\pm\frac{\sqrt3}2i.

Sum of Re⁡+Im⁡\operatorname{Re}+\operatorname{Im} =0−1+1=0=0-1+1=0.

Answer: 0