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If `alpha,beta` are the roots of the equation `2x^(2) - 2(1+n)^(2) x+(1 + n^(2)+ n^(4))=0` then what is the value of `alpha^(2) + beta^(2)` ?

A

`2n^(2)`

B

`2n^(4)`

C

2

D

`n^(2)`

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The correct Answer is:
To find the value of \( \alpha^2 + \beta^2 \) for the roots \( \alpha \) and \( \beta \) of the quadratic equation \[ 2x^2 - 2(1+n)^2 x + (1 + n^2 + n^4) = 0, \] we can follow these steps: ### Step 1: Identify the coefficients The given quadratic equation can be written in the standard form \( ax^2 + bx + c = 0 \), where: - \( a = 2 \) - \( b = -2(1+n)^2 \) - \( c = 1 + n^2 + n^4 \) ### Step 2: Calculate \( \alpha + \beta \) and \( \alpha \beta \) Using Vieta's formulas: - The sum of the roots \( \alpha + \beta = -\frac{b}{a} \) - The product of the roots \( \alpha \beta = \frac{c}{a} \) Calculating \( \alpha + \beta \): \[ \alpha + \beta = -\frac{-2(1+n)^2}{2} = (1+n)^2 \] Calculating \( \alpha \beta \): \[ \alpha \beta = \frac{1 + n^2 + n^4}{2} \] ### Step 3: Use the formula for \( \alpha^2 + \beta^2 \) We can use the identity: \[ \alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2\alpha\beta \] Substituting the values we found: \[ \alpha^2 + \beta^2 = ((1+n)^2)^2 - 2 \cdot \frac{1 + n^2 + n^4}{2} \] ### Step 4: Simplify the expression First, calculate \( ((1+n)^2)^2 \): \[ ((1+n)^2)^2 = (1+n)^4 \] Now, substituting back: \[ \alpha^2 + \beta^2 = (1+n)^4 - (1 + n^2 + n^4) \] ### Step 5: Expand and simplify Expanding \( (1+n)^4 \): \[ (1+n)^4 = 1 + 4n + 6n^2 + 4n^3 + n^4 \] Now, substituting this into the equation: \[ \alpha^2 + \beta^2 = (1 + 4n + 6n^2 + 4n^3 + n^4) - (1 + n^2 + n^4) \] This simplifies to: \[ \alpha^2 + \beta^2 = 4n + 6n^2 + 4n^3 + n^4 - 1 - n^2 - n^4 \] \[ = 4n + (6n^2 - n^2) + (4n^3) + (n^4 - n^4) \] \[ = 4n + 5n^2 + 4n^3 \] ### Final Result Thus, the value of \( \alpha^2 + \beta^2 \) is: \[ \alpha^2 + \beta^2 = 5n^2 + 4n + 4n^3 \]

To find the value of \( \alpha^2 + \beta^2 \) for the roots \( \alpha \) and \( \beta \) of the quadratic equation \[ 2x^2 - 2(1+n)^2 x + (1 + n^2 + n^4) = 0, \] we can follow these steps: ...
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