Verified Solution • 2025–26 Session moderate

QJEEM24Mad4ff: JEE Main 2024 Mathematics - Class 11 JEEM24Mad4ff Solution: Let and be the sum and the product of all the non-zero…

Let α\alpha and β\beta be the sum and the product of all the non-zero solutions of the equation (zˉ)2+∣z∣=0,z∈C(\bar{z})^2+|z|=0, z \in C . Then 4(α2+β2)4(\alpha^2+\beta^2) is equal to :

Multiple Choice Options

  • A 4
  • B 2
  • C 6
  • D 8

Step-by-Step Verified Solution

amp;(zˉ)2+∣z∣=0... (1)amp;z2+∣zˉ∣=0... (2)\begin{aligned}& (\bar{z})^2+|z|=0 \quad \text{... (1)}\\& z^2+|\bar{z}|=0 \quad \text{... (2)}\end{aligned}

From equation (1) and (2)

amp; as ∣z∣=∣zˉ∣amp;⇒(zˉ)2=z2amp;⇒z=zˉ or z=−zˉamp;⇒Im⁡(z)=0 or Re⁡(z)=0\begin{aligned}& \text { as }|z|=|\bar{z}| \\& \Rightarrow \quad(\bar{z})^2=z^2 \\& \Rightarrow \quad z=\bar{z} \text { or } z=-\bar{z} \\& \Rightarrow \operatorname{Im}(z)=0 \text { or } \operatorname{Re}(z)=0\end{aligned}

Case I : If Im⁡(z)=0\operatorname{Im}(z)=0

⇒z=x\Rightarrow z=x

Putting value of zz in equation (1)

amp;x2+∣x∣=0amp;⇒x=0[Rejected]\begin{aligned}& x^2+|x|=0 \\& \Rightarrow x=0 \quad \text{[Rejected]}\end{aligned}

Case II : If Re⁡(z)=0\operatorname{Re}(z)=0

⇒z=iy\Rightarrow z=i y

Putting value of zz in equation (1)

amp;−y2+∣y∣=0amp;y=±1 as y≠0\begin{aligned}& -y^2+|y|=0 \\& y= \pm 1 \text { as } y \neq 0\end{aligned}

Hence, z=±iz= \pm i are the solution of the given equation

amp;⇒α=i−i=0amp; and β=i(−i)=1amp;⇒4(α2+β2)=4(0+1)amp;=4\begin{aligned}& \Rightarrow \alpha=i-i=0 \\& \text { and } \beta=i(-i)=1 \\& \Rightarrow \quad 4\left(\alpha^2+\beta^2\right)=4(0+1) \\& \quad=4\end{aligned}

∴\therefore Option (3) is correct

Related Learning Resources & Exam Preparation