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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+1=0` then `alpha^(101)+beta^(107)` is equal to

A

2

B

`-1`

C

0

D

1

Text Solution

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The correct Answer is:
To solve the problem, we need to find the values of \( \alpha^{101} + \beta^{107} \) where \( \alpha \) and \( \beta \) are distinct roots of the equation \( x^2 + 1 = 0 \). ### Step-by-step Solution: 1. **Identify the Roots**: The equation \( x^2 + 1 = 0 \) can be rewritten as: \[ x^2 = -1 \] The roots of this equation are: \[ \alpha = i \quad \text{and} \quad \beta = -i \] 2. **Calculate \( \alpha^{101} \)**: We can express \( \alpha \) in exponential form: \[ \alpha = i = e^{i\frac{\pi}{2}} \] Therefore, we can compute \( \alpha^{101} \): \[ \alpha^{101} = (e^{i\frac{\pi}{2}})^{101} = e^{i\frac{101\pi}{2}} \] To simplify \( e^{i\frac{101\pi}{2}} \), we can reduce \( \frac{101\pi}{2} \) modulo \( 2\pi \): \[ \frac{101\pi}{2} = 50\pi + \frac{\pi}{2} \quad \text{(since } 50\pi \text{ is a multiple of } 2\pi\text{)} \] Therefore: \[ e^{i\frac{101\pi}{2}} = e^{i\frac{\pi}{2}} = i \] 3. **Calculate \( \beta^{107} \)**: Similarly, for \( \beta \): \[ \beta = -i = e^{-i\frac{\pi}{2}} \] Thus, we compute \( \beta^{107} \): \[ \beta^{107} = (e^{-i\frac{\pi}{2}})^{107} = e^{-i\frac{107\pi}{2}} \] Reducing \( -\frac{107\pi}{2} \) modulo \( 2\pi \): \[ -\frac{107\pi}{2} = -53\pi - \frac{\pi}{2} \quad \text{(since } -53\pi \text{ is a multiple of } 2\pi\text{)} \] Therefore: \[ e^{-i\frac{107\pi}{2}} = e^{-i\frac{\pi}{2}} = -i \] 4. **Combine the Results**: Now we can combine the results: \[ \alpha^{101} + \beta^{107} = i + (-i) = 0 \] ### Final Answer: \[ \alpha^{101} + \beta^{107} = 0 \]

To solve the problem, we need to find the values of \( \alpha^{101} + \beta^{107} \) where \( \alpha \) and \( \beta \) are distinct roots of the equation \( x^2 + 1 = 0 \). ### Step-by-step Solution: 1. **Identify the Roots**: The equation \( x^2 + 1 = 0 \) can be rewritten as: \[ x^2 = -1 ...
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