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If a,b are non zero real numbers and alp...

If a,b are non zero real numbers and `alpha, beta` the roots of `x^(2)+ax+b=0`, then

A

`alpha^(2),beta^(2)` are the roots of `x^(2)-(2b-a^(2))x+a^(2)=0`

B

`1/(alpha),1/(beta)` are the roots of `bx^(2)+ax+1=0`

C

`(alpha)/(beta),(beta)/(alpha)` are the roots of `bx^(2)+(2b-a^(2))x+b=0`

D

`(alpha-1),(beta-1)` are the roots of the equation `x^(2)+x(a+2)+1+a+b=0`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we start with the given quadratic equation: \[ x^2 + ax + b = 0 \] ### Step 1: Identify the roots Let the roots of the equation be \( \alpha \) and \( \beta \). According to Vieta's formulas: - The sum of the roots \( \alpha + \beta = -a \) - The product of the roots \( \alpha \beta = b \) ### Step 2: Analyze the options We need to check the validity of the given options based on the relationships we derived from Vieta's formulas. #### Option 1: The product of the roots is \( \alpha^2 + \beta^2 \) and should equal \( a^2 \). - We know \( \alpha^2 + \beta^2 = (\alpha + \beta)^2 - 2\alpha\beta \). - Substituting the values, we get: \[ \alpha^2 + \beta^2 = (-a)^2 - 2b = a^2 - 2b \] - For this option to hold true, we would need \( a^2 - 2b = a^2 \), which implies \( b = 0 \). This contradicts the condition that \( b \) is non-zero. #### Option 2: The product of the roots is \( \frac{1}{b} \) and the sum is \( \frac{1}{\alpha} + \frac{1}{\beta} \). - The product of the roots \( \frac{1}{\alpha} \cdot \frac{1}{\beta} = \frac{1}{\alpha \beta} = \frac{1}{b} \) is correct. - The sum of the roots \( \frac{1}{\alpha} + \frac{1}{\beta} = \frac{\alpha + \beta}{\alpha \beta} = \frac{-a}{b} \) is also correct. #### Option 3: The product of the roots is \( \frac{1}{b} \) and the sum is \( \frac{1}{\alpha + \beta} \). - The product of the roots \( \frac{1}{\alpha} \cdot \frac{1}{\beta} = \frac{1}{b} \) is correct. - However, the sum \( \frac{1}{\alpha + \beta} = \frac{1}{-a} \) does not match \( \frac{-a}{b} \). ### Conclusion: From the analysis, we find that: - Option 1 is incorrect. - Option 2 is correct. - Option 3 is incorrect. ### Final Answer: The correct option is **Option 2**.
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