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"Let" P=[{:(,"cos"(pi)/(9),"sin"(pi)/(9)...

`"Let" P=[{:(,"cos"(pi)/(9),"sin"(pi)/(9)),(,-"sin"(pi)/(9),"cos"(pi)/(9)):}]` and `alpha, beta, gamma` be non-zero real number such that `alpha p^(6)+betap^(3)+gammal` is the zero matrix. Then find the value of `(alpha^(2)+beta^(2)+gamma^(2))^(alpha-betaxxbeta-gammaxxgamma-alpha)`

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To solve the problem, we need to analyze the given matrix \( P \) and the equation involving \( \alpha, \beta, \gamma \). Let's break it down step by step. ### Step 1: Define the Matrix \( P \) The matrix \( P \) is defined as: \[ P = \begin{pmatrix} \cos\left(\frac{\pi}{9}\right) & \sin\left(\frac{\pi}{9}\right) \\ -\sin\left(\frac{\pi}{9}\right) & \cos\left(\frac{\pi}{9}\right) \end{pmatrix} \] This is a rotation matrix that represents a rotation by an angle of \( \frac{\pi}{9} \). ### Step 2: Calculate \( P^2 \) To find \( P^2 \), we multiply \( P \) by itself: \[ P^2 = P \cdot P = \begin{pmatrix} \cos\left(\frac{\pi}{9}\right) & \sin\left(\frac{\pi}{9}\right) \\ -\sin\left(\frac{\pi}{9}\right) & \cos\left(\frac{\pi}{9}\right) \end{pmatrix} \cdot \begin{pmatrix} \cos\left(\frac{\pi}{9}\right) & \sin\left(\frac{\pi}{9}\right) \\ -\sin\left(\frac{\pi}{9}\right) & \cos\left(\frac{\pi}{9}\right) \end{pmatrix} \] Using the multiplication of matrices, we find: \[ P^2 = \begin{pmatrix} \cos\left(\frac{2\pi}{9}\right) & \sin\left(\frac{2\pi}{9}\right) \\ -\sin\left(\frac{2\pi}{9}\right) & \cos\left(\frac{2\pi}{9}\right) \end{pmatrix} \] ### Step 3: Calculate \( P^3 \) Continuing this process, we can find \( P^3 \): \[ P^3 = P^2 \cdot P = \begin{pmatrix} \cos\left(\frac{2\pi}{9}\right) & \sin\left(\frac{2\pi}{9}\right) \\ -\sin\left(\frac{2\pi}{9}\right) & \cos\left(\frac{2\pi}{9}\right) \end{pmatrix} \cdot P \] This results in: \[ P^3 = \begin{pmatrix} \cos\left(\frac{3\pi}{9}\right) & \sin\left(\frac{3\pi}{9}\right) \\ -\sin\left(\frac{3\pi}{9}\right) & \cos\left(\frac{3\pi}{9}\right) \end{pmatrix} \] ### Step 4: Calculate \( P^6 \) Following the same logic: \[ P^6 = P^3 \cdot P^3 = \begin{pmatrix} \cos\left(\frac{6\pi}{9}\right) & \sin\left(\frac{6\pi}{9}\right) \\ -\sin\left(\frac{6\pi}{9}\right) & \cos\left(\frac{6\pi}{9}\right) \end{pmatrix} \] ### Step 5: Set Up the Equation Given the equation: \[ \alpha P^6 + \beta P^3 + \gamma I = 0 \] Substituting the values we calculated: \[ \alpha \begin{pmatrix} \cos\left(\frac{6\pi}{9}\right) & \sin\left(\frac{6\pi}{9}\right) \\ -\sin\left(\frac{6\pi}{9}\right) & \cos\left(\frac{6\pi}{9}\right) \end{pmatrix} + \beta \begin{pmatrix} \cos\left(\frac{3\pi}{9}\right) & \sin\left(\frac{3\pi}{9}\right) \\ -\sin\left(\frac{3\pi}{9}\right) & \cos\left(\frac{3\pi}{9}\right) \end{pmatrix} + \gamma \begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix} = 0 \] ### Step 6: Solve for \( \alpha, \beta, \gamma \) From the equation, we can derive the following relationships: 1. The coefficients of the matrix must equal zero. 2. This gives us a system of equations to solve. ### Step 7: Find \( \alpha, \beta, \gamma \) From the relationships derived, we find: - \( \alpha + \beta = 0 \) implies \( \beta = -\alpha \) - \( \alpha - \beta = 2\gamma \) implies \( 2\alpha = 2\gamma \) or \( \alpha = \gamma \) ### Step 8: Substitute Values Substituting \( \beta = -\alpha \) and \( \gamma = \alpha \) into \( \alpha^2 + \beta^2 + \gamma^2 \): \[ \alpha^2 + (-\alpha)^2 + \alpha^2 = 3\alpha^2 \] ### Step 9: Calculate the Exponent The exponent simplifies as follows: \[ \alpha - \beta = 2\alpha, \quad \beta - \gamma = -2\alpha, \quad \gamma - \alpha = 0 \] Thus, the entire exponent becomes: \[ (2\alpha)(-2\alpha)(0) = 0 \] ### Step 10: Final Result Since any non-zero number raised to the power of 0 is 1: \[ (3\alpha^2)^0 = 1 \] ### Final Answer The value is: \[ \boxed{1} \]
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