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If alpha, beta in C are distinct roots o...

If `alpha, beta in C` are distinct roots of the equation `x^2-x+1=0` then `alpha^(101)+beta^(107)` is equal to

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To solve the problem, we need to find the value of \( \alpha^{101} + \beta^{107} \), where \( \alpha \) and \( \beta \) are the distinct roots of the equation \( x^2 - x + 1 = 0 \). ### Step 1: Find the roots of the quadratic equation The roots of the quadratic equation \( x^2 - x + 1 = 0 \) can be found using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 1 \), \( b = -1 \), and \( c = 1 \). Substituting these values into the formula: \[ x = \frac{1 \pm \sqrt{(-1)^2 - 4 \cdot 1 \cdot 1}}{2 \cdot 1} = \frac{1 \pm \sqrt{1 - 4}}{2} = \frac{1 \pm \sqrt{-3}}{2} \] This simplifies to: \[ x = \frac{1 \pm i\sqrt{3}}{2} \] Thus, the roots are: \[ \alpha = \frac{1 + i\sqrt{3}}{2}, \quad \beta = \frac{1 - i\sqrt{3}}{2} \] ### Step 2: Express powers of the roots in terms of \( \omega \) Notice that \( \alpha \) and \( \beta \) can be expressed in terms of the cube roots of unity. The cube roots of unity are \( 1, \omega, \omega^2 \), where \( \omega = e^{2\pi i / 3} = \frac{-1 + i\sqrt{3}}{2} \). We can observe that: \[ \alpha = \omega^2, \quad \beta = \omega \] ### Step 3: Calculate \( \alpha^{101} + \beta^{107} \) Now we can compute \( \alpha^{101} + \beta^{107} \): \[ \alpha^{101} = (\omega^2)^{101} = \omega^{202} \] \[ \beta^{107} = \omega^{107} \] ### Step 4: Simplify using properties of \( \omega \) Since \( \omega^3 = 1 \), we can reduce the exponents modulo 3: \[ 202 \mod 3 = 1 \quad \text{(since } 202 = 3 \cdot 67 + 1\text{)} \] \[ 107 \mod 3 = 2 \quad \text{(since } 107 = 3 \cdot 35 + 2\text{)} \] Thus: \[ \alpha^{101} = \omega^{202} = \omega^1 = \omega \] \[ \beta^{107} = \omega^{107} = \omega^2 \] ### Step 5: Combine the results Now we can combine the results: \[ \alpha^{101} + \beta^{107} = \omega + \omega^2 \] ### Step 6: Use the property of cube roots of unity From the property of cube roots of unity, we know: \[ 1 + \omega + \omega^2 = 0 \implies \omega + \omega^2 = -1 \] ### Final Result Thus, we find: \[ \alpha^{101} + \beta^{107} = -1 \] The final answer is: \[ \boxed{-1} \]

To solve the problem, we need to find the value of \( \alpha^{101} + \beta^{107} \), where \( \alpha \) and \( \beta \) are the distinct roots of the equation \( x^2 - x + 1 = 0 \). ### Step 1: Find the roots of the quadratic equation The roots of the quadratic equation \( x^2 - x + 1 = 0 \) can be found using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 1 \), \( b = -1 \), and \( c = 1 \). ...
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