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if alpha&betaare the roots of the quadra...

if `alpha&beta`are the roots of the quadratic equation `ax^2 + bx + c = 0`, then the quadratic equation `ax^2-bx(x-1)+c(x-1)^2 =0` has roots

A

`alpha/(1-alpha), beta/(1-beta)`

B

`(1-alpha)/alpha , (1 -beta)/beta`

C

`alpha/(1 +alpha)`, beta/(1+beta)

D

`(1 + alpha)/alpha, ( 1 + beta)/beta `

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The correct Answer is:
To solve the problem, we need to find the roots of the quadratic equation given by: \[ ax^2 - bx(x - 1) + c(x - 1)^2 = 0 \] ### Step 1: Expand the equation Start by expanding the terms in the equation: \[ ax^2 - bx(x - 1) + c(x - 1)^2 = ax^2 - bx^2 + bx + c(x^2 - 2x + 1) \] Expanding \(c(x - 1)^2\): \[ c(x - 1)^2 = c(x^2 - 2x + 1) = cx^2 - 2cx + c \] Now, substituting this back into the equation: \[ ax^2 - bx^2 + bx + cx^2 - 2cx + c = 0 \] ### Step 2: Combine like terms Now, combine the \(x^2\) terms and the \(x\) terms: \[ (a - b + c)x^2 + (b - 2c)x + c = 0 \] ### Step 3: Identify coefficients From the combined equation, we can identify the coefficients: - Coefficient of \(x^2\): \(A = a - b + c\) - Coefficient of \(x\): \(B = b - 2c\) - Constant term: \(C = c\) ### Step 4: Find the sum and product of the roots Using Vieta's formulas, we know: 1. The sum of the roots \(P + Q = -\frac{B}{A} = -\frac{b - 2c}{a - b + c}\) 2. The product of the roots \(PQ = \frac{C}{A} = \frac{c}{a - b + c}\) ### Step 5: Substitute known values We know from the original quadratic equation \(ax^2 + bx + c = 0\) that: - The sum of the roots \(\alpha + \beta = -\frac{b}{a}\) - The product of the roots \(\alpha \beta = \frac{c}{a}\) ### Step 6: Express \(P + Q\) and \(PQ\) in terms of \(\alpha\) and \(\beta\) Now, we can express \(P + Q\) and \(PQ\) in terms of \(\alpha\) and \(\beta\): 1. For the sum: \[ P + Q = -\frac{b - 2c}{a - b + c} = \frac{2c - b}{a - b + c} \] Substituting \(b = -a(\alpha + \beta)\) and \(c = a\alpha\beta\), we can express this in terms of \(\alpha\) and \(\beta\). 2. For the product: \[ PQ = \frac{c}{a - b + c} = \frac{c}{a - (-a(\alpha + \beta)) + c} = \frac{c}{a(1 + \alpha + \beta) + c} \] ### Final Step: Roots in terms of \(\alpha\) and \(\beta\) After simplification, we find that: \[ P = \frac{\alpha}{1 + \alpha}, \quad Q = \frac{\beta}{1 + \beta} \] Thus, the roots of the quadratic equation \(ax^2 - bx(x - 1) + c(x - 1)^2 = 0\) are: \[ P = \frac{\alpha}{1 + \alpha}, \quad Q = \frac{\beta}{1 + \beta} \]
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