If $1, \omega, \omega^2, \ldots \omega^{10}$ are 11 th roots of unity, then product of these roots is 1

If $1, \omega, \omega^2, \ldots \omega^{10}$ are 11 th roots of unity, then product of these roots is 1
  1. $\omega$
  2. -1
  3. 1
  4. $\omega^2$

Solution

Given $1, \omega, \omega^2, \ldots, \omega^{10}$ are 11 th roots of unity. $\Rightarrow 1, \omega, \omega^2, \ldots, \omega^{10}$ are the roots of the equation given below. or $ \begin{aligned} & x=(1)^{1 / 11} \\ or \\ & x^{11}=1 \\ & \Rightarrow \quad x^{11}-1=0 \\ & \end{aligned} $ Since, we know that product of roots of a polynomial of degree $n=(-1)^n \cdot \frac{\text { Constant term }}{\text { Coefficient of } x^n}$ $ \therefore 1 \cdot \omega \cdot \omega^2 \ldots \omega^{10}=\frac{(-1)^{11}(-1)}{1}=1 $

Asked in: AP EAMCET 2021 (25 Aug Shift 2)

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