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If alpha, beta are the roots of the equ...

If ` alpha, beta` are the roots of the equation ` ax^(2) -bx +c=0` then equation ` (a+cy)^(2) =b^(2) y` has the roots

A

`1/alpha , 1/beta`

B

` alpha^(2), beta^(2) `

C

`alpha/beta , beta/alpha`

D

`1/alpha^(2), 1/beta^(2) `

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the roots of the equation \( (a + cy)^2 = b^2 y \) given that \( \alpha \) and \( \beta \) are the roots of the equation \( ax^2 - bx + c = 0 \). ### Step-by-Step Solution: 1. **Start with the given equation**: \[ (a + cy)^2 = b^2 y \] 2. **Expand the left-hand side**: \[ a^2 + 2acy + c^2y^2 = b^2y \] 3. **Rearrange the equation**: \[ c^2y^2 + (2ac - b^2)y + a^2 = 0 \] 4. **Identify coefficients**: Here, we can identify the coefficients of the quadratic equation: - \( A = c^2 \) - \( B = 2ac - b^2 \) - \( C = a^2 \) 5. **Use Vieta's formulas**: According to Vieta's formulas, the sum and product of the roots \( m \) and \( n \) of the quadratic equation \( Ay^2 + By + C = 0 \) are given by: \[ m + n = -\frac{B}{A} \quad \text{and} \quad mn = \frac{C}{A} \] 6. **Calculate the sum of the roots**: \[ m + n = -\frac{2ac - b^2}{c^2} = \frac{b^2 - 2ac}{c^2} \] 7. **Calculate the product of the roots**: \[ mn = \frac{a^2}{c^2} \] 8. **Relate the results to the roots \( \alpha \) and \( \beta \)**: From the original quadratic equation \( ax^2 - bx + c = 0 \), we know: - \( \alpha + \beta = \frac{b}{a} \) - \( \alpha \beta = \frac{c}{a} \) 9. **Express \( m + n \) and \( mn \) in terms of \( \alpha \) and \( \beta \)**: - Since \( m + n = \frac{b^2 - 2ac}{c^2} \) and \( mn = \frac{a^2}{c^2} \), we can express these in terms of \( \alpha \) and \( \beta \): \[ m + n = \frac{b^2}{c^2} - \frac{2a}{c} \quad \text{and} \quad mn = \frac{a^2}{c^2} \] 10. **Final roots**: The roots of the equation \( (a + cy)^2 = b^2 y \) are: \[ m = \frac{1}{\beta^2}, \quad n = \frac{1}{\alpha^2} \] ### Summary: The roots of the equation \( (a + cy)^2 = b^2 y \) are \( \frac{1}{\beta^2} \) and \( \frac{1}{\alpha^2} \).
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