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If the zeroes of the quadratic polynomia...

If the zeroes of the quadratic polynomial `x^(2)+(a+1)x+b` are 2 and -3 ,then

A

`x^(2)+(a+1)x+b` are 2 and -3 ,then

B

`a=5,b=-1`

C

`a=2,b=-6`

D

`a=0,b=-6`

Text Solution

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The correct Answer is:
To solve the problem, we need to find the values of \( a \) and \( b \) in the quadratic polynomial \( x^2 + (a+1)x + b \) given that its zeroes are \( 2 \) and \( -3 \). ### Step-by-Step Solution: 1. **Identify the Zeroes**: The zeroes of the polynomial are given as \( \alpha = 2 \) and \( \beta = -3 \). 2. **Use the Sum of Zeroes**: The sum of the zeroes \( \alpha + \beta \) can be calculated: \[ \alpha + \beta = 2 + (-3) = -1 \] According to the relationship between the coefficients and the roots of a polynomial, we have: \[ \alpha + \beta = -\frac{b}{a} \] Here, \( a = 1 \) (the coefficient of \( x^2 \)) and \( b = a + 1 \) (the coefficient of \( x \)). Therefore: \[ -1 = -\frac{a + 1}{1} \] Simplifying this gives: \[ -1 = -(a + 1) \] Thus: \[ 1 = a + 1 \] Rearranging gives: \[ a = 0 \] 3. **Use the Product of Zeroes**: The product of the zeroes \( \alpha \cdot \beta \) can be calculated: \[ \alpha \cdot \beta = 2 \cdot (-3) = -6 \] According to the relationship between the coefficients and the roots of a polynomial, we have: \[ \alpha \cdot \beta = \frac{c}{a} \] Here, \( c = b \) (the constant term). Therefore: \[ -6 = \frac{b}{1} \] Thus: \[ b = -6 \] 4. **Final Values**: We have found: \[ a = 0 \quad \text{and} \quad b = -6 \] ### Conclusion: The values of \( a \) and \( b \) are \( 0 \) and \( -6 \) respectively.
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