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If 1,`omega,omega^2,omega^3,...,omega^(n-1)` be the n,nth roots of unity,the value of `(9-omega)(9-omega^2)...(9-omega^(n-1))` will be :

A

0

B

`(9^(n-1))/8`

C

`(8^(n-1))/3`

D

none of these

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The correct Answer is:
To solve the problem, we need to find the value of the product \((9 - \omega)(9 - \omega^2) \cdots (9 - \omega^{n-1})\), where \(\omega\) is a primitive \(n\)th root of unity. ### Step-by-step Solution: 1. **Understanding Roots of Unity**: The \(n\)th roots of unity are given by \(1, \omega, \omega^2, \ldots, \omega^{n-1}\), where \(\omega = e^{2\pi i/n}\). These roots satisfy the equation \(x^n - 1 = 0\). 2. **Factorization of Polynomial**: The polynomial \(x^n - 1\) can be factored as: \[ x^n - 1 = (x - 1)(x - \omega)(x - \omega^2) \cdots (x - \omega^{n-1}). \] 3. **Setting Up the Equation**: We can express \(x^n - 1\) in terms of \(x\): \[ x^n - 1 = 0 \implies x^n = 1. \] Thus, we can write: \[ x^n - 1 = (x - 1)(x - \omega)(x - \omega^2) \cdots (x - \omega^{n-1}). \] 4. **Substituting \(x = 9\)**: We substitute \(x = 9\) into the equation: \[ 9^n - 1 = (9 - 1)(9 - \omega)(9 - \omega^2) \cdots (9 - \omega^{n-1}). \] 5. **Calculating the Left Side**: The left side becomes: \[ 9^n - 1 = 9^n - 1. \] 6. **Calculating the Right Side**: The right side simplifies to: \[ 8(9 - \omega)(9 - \omega^2) \cdots (9 - \omega^{n-1}). \] 7. **Equating Both Sides**: Now we equate both sides: \[ 9^n - 1 = 8(9 - \omega)(9 - \omega^2) \cdots (9 - \omega^{n-1}). \] 8. **Isolating the Product**: To isolate the product, we divide both sides by 8: \[ \frac{9^n - 1}{8} = (9 - \omega)(9 - \omega^2) \cdots (9 - \omega^{n-1}). \] 9. **Final Result**: Thus, the value of the product \((9 - \omega)(9 - \omega^2) \cdots (9 - \omega^{n-1})\) is: \[ \frac{9^n - 1}{8}. \]
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