Home
Class 12
MATHS
If alpha ,beta and gamma are the roots o...

If `alpha ,beta and gamma` are the roots of
`x^3-2x^2+3x-4 =0 `, then find
`sumalpha^2beta^2`

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of \( \sum \alpha^2 \beta^2 \) where \( \alpha, \beta, \gamma \) are the roots of the polynomial equation \( x^3 - 2x^2 + 3x - 4 = 0 \), we can follow these steps: ### Step 1: Identify the coefficients The given polynomial is: \[ x^3 - 2x^2 + 3x - 4 = 0 \] From this, we can identify the coefficients: - \( a = 1 \) - \( b = -2 \) - \( c = 3 \) - \( d = -4 \) ### Step 2: Use Vieta's formulas According to Vieta's formulas, for the roots \( \alpha, \beta, \gamma \): 1. The sum of the roots: \[ \alpha + \beta + \gamma = -\frac{b}{a} = -\frac{-2}{1} = 2 \] 2. The sum of the products of the roots taken two at a time: \[ \alpha \beta + \beta \gamma + \gamma \alpha = \frac{c}{a} = \frac{3}{1} = 3 \] 3. The product of the roots: \[ \alpha \beta \gamma = -\frac{d}{a} = -\frac{-4}{1} = 4 \] ### Step 3: Find \( \sum \alpha^2 \beta^2 \) We want to find: \[ \sum \alpha^2 \beta^2 = \alpha^2 \beta^2 + \beta^2 \gamma^2 + \gamma^2 \alpha^2 \] This can be rewritten using the identity: \[ \sum \alpha^2 \beta^2 = (\alpha \beta + \beta \gamma + \gamma \alpha)^2 - 2 \alpha \beta \gamma (\alpha + \beta + \gamma) \] ### Step 4: Substitute the known values Substituting the values we found: \[ \sum \alpha^2 \beta^2 = (3)^2 - 2 \cdot 4 \cdot 2 \] Calculating this gives: \[ \sum \alpha^2 \beta^2 = 9 - 16 = -7 \] ### Final Answer Thus, the value of \( \sum \alpha^2 \beta^2 \) is: \[ \boxed{-7} \]
Promotional Banner

Similar Questions

Explore conceptually related problems

If alpha ,beta and gamma are the roots of x^3-2x^2+3x-4 =0 , then find (i) sumalpha^2beta^2 (ii)sumalpha beta(alpha+beta)

If alpha , beta , gamma are the roots of x^3 +px^2 +qx +r=0 then find sum alpha^2 beta^2

If alpha , beta , gamma are the roots of x^3 +px^2 +qx +r=0 then find sum alpha^2

If alpha , beta , gamma are the roots of x^3 +px^2 +qx +r=0 then find sum alpha^3

If alpha , beta , gamma are the roots of x^3 +px^2 +qx +r=0 then find sum alpha^2 beta + sum alpha beta ^2

If alpha , beta , gamma are the roots of x^3 +px^2 +qx +r=0 then find sum (1)/( alpha )

If alpha, beta and 1 are the roots of x^3-2x^2-5x+6=0 , then find alpha and beta

If alpha , beta , gamma are the roots of the equation x^3 -6x^2 +11 x +6=0 then sum alpha^2 beta =

If alpha , beta , gamma are the roots of x^3 -px^2 +qx -r=0 and r ne 0 then find (1)/( alpha^2) +(1)/( beta^2) +(1)/( gamma ^2) in terms of p,q ,r

If alpha , beta , gamma are the roots of the equation x^3 +px^2 +qx +r=0 then sum alpha^2 ( beta + gamma)=