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If w ne 1 is a cube root of unity and De...

If `w ne 1` is a cube root of unity and `Delta=|{:(x+w^(2),w,1),(w,w^(2),1+x),(1,x+w,w^(2)):}|=0`, then value of `x` is

A

`0`

B

`2`

C

`-1`

D

None of these

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The correct Answer is:
To solve the problem, we start with the determinant given by: \[ \Delta = \begin{vmatrix} x + \omega^2 & \omega & 1 \\ \omega & \omega^2 & 1 + x \\ 1 & x + \omega & \omega^2 \end{vmatrix} = 0 \] ### Step 1: Use the property of cube roots of unity Recall that for cube roots of unity, \(1 + \omega + \omega^2 = 0\). This property will help simplify our calculations. ### Step 2: Simplify the determinant We can simplify the determinant by performing row operations. We will add all three rows together: \[ R_1 + R_2 + R_3 \rightarrow R_1 \] This gives us: \[ \Delta = \begin{vmatrix} (x + \omega^2) + \omega + 1 & \omega & 1 \\ \omega & \omega^2 & 1 + x \\ 1 & x + \omega & \omega^2 \end{vmatrix} \] Calculating the first row: \[ x + \omega^2 + \omega + 1 = x + 0 = x \] So we have: \[ \Delta = \begin{vmatrix} x & \omega & 1 \\ \omega & \omega^2 & 1 + x \\ 1 & x + \omega & \omega^2 \end{vmatrix} \] ### Step 3: Expand the determinant Now we can expand the determinant using the first row: \[ \Delta = x \begin{vmatrix} \omega^2 & 1 + x \\ x + \omega & \omega^2 \end{vmatrix} - \omega \begin{vmatrix} \omega & 1 + x \\ 1 & \omega^2 \end{vmatrix} + 1 \begin{vmatrix} \omega & \omega^2 \\ 1 & x + \omega \end{vmatrix} \] ### Step 4: Calculate the 2x2 determinants 1. For the first determinant: \[ \begin{vmatrix} \omega^2 & 1 + x \\ x + \omega & \omega^2 \end{vmatrix} = \omega^2 \cdot \omega^2 - (1 + x)(x + \omega) = \omega^4 - (1 + x)(x + \omega) \] 2. For the second determinant: \[ \begin{vmatrix} \omega & 1 + x \\ 1 & \omega^2 \end{vmatrix} = \omega \cdot \omega^2 - (1)(1 + x) = \omega^3 - (1 + x) = 1 - (1 + x) = -x \] 3. For the third determinant: \[ \begin{vmatrix} \omega & \omega^2 \\ 1 & x + \omega \end{vmatrix} = \omega(x + \omega) - \omega^2 = \omega x + \omega^2 - \omega^2 = \omega x \] ### Step 5: Substitute back into the determinant Now substituting back into the determinant: \[ \Delta = x(\omega^4 - (1 + x)(x + \omega)) + \omega x - \omega^2 x \] Since \(\omega^4 = \omega\), we simplify: \[ \Delta = x(\omega - (1 + x)(x + \omega)) + \omega x - \omega^2 x \] ### Step 6: Set the determinant to zero Now we set \(\Delta = 0\): \[ x(\omega - (1 + x)(x + \omega)) + \omega x - \omega^2 x = 0 \] ### Step 7: Solve for \(x\) We can factor out \(x\): \[ x(\omega - (1 + x)(x + \omega) + \omega - \omega^2) = 0 \] This gives us two cases: 1. \(x = 0\) 2. The expression in the parentheses equals zero. Since we are looking for values of \(x\) that satisfy the determinant being zero, we find that: \[ x = 0 \] Thus, the value of \(x\) is: \[ \boxed{0} \]

To solve the problem, we start with the determinant given by: \[ \Delta = \begin{vmatrix} x + \omega^2 & \omega & 1 \\ \omega & \omega^2 & 1 + x \\ 1 & x + \omega & \omega^2 \end{vmatrix} = 0 ...
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