If $\mathrm{w}=\frac{-1+\mathrm{i} \sqrt{3}}{2}$, where $\mathrm{i}=\sqrt{-1}$, then the value of…

If $\mathrm{w}=\frac{-1+\mathrm{i} \sqrt{3}}{2}$, where $\mathrm{i}=\sqrt{-1}$, then the value of $\left(3+w+3 w^2\right)^4$ is
  1. 16
  2. -16
  3. 16 w
  4. $16 w^2$

Solution

$\omega$ is a complex cube root of unity $\begin{array}{ll} \therefore \quad & \omega=1 ...(i)\\ \therefore \quad & 1+\omega+\omega^2=0, \\ \therefore \quad & \left(3+\omega+3 \omega^2\right)^4 ...(ii)\\ & =(3+\omega+3(-1-\omega))^4 \\ & =(3+\omega-3-3 \omega)^4 \\ & =(-2 \omega)^4 \\ & =16 \omega^4 \\ & =16 \omega^3 \times \omega \\ & =16 \omega \end{array}$ ...[from (ii)] ...[from (i)]

Asked in: MHT CET 2024 (10 May Shift 1)

Practice more Complex Number questions on Aicharya