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Statement -1: The equation who roots are...

Statement -1: The equation who roots are reciprocal of the roots of the equation `10x^(2) -x-5=0" is " 5x^(2) +x-10=0`
and
Statement -2 : To obtain a quadratic equation whose roots are reciprocal of the roots of the given equation `ax^(2) +bx +c=0` change the coefficients a,b,c,to c,b,a. `(c ne 0)`

A

Statement -1 is True, Statement -2 is True, Statement -2 is a correct explanation for statement -11

B

Statement -1 is True, Statement -2 is True , Statement -2 is NOT a correct explanation for Statement -11

C

Statement -1 is True, Statement -2 is False

D

Statement -1 is Flase, Statement -2 is True

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to verify both statements regarding the quadratic equations and their roots. ### Given: 1. **Statement 1**: The equation whose roots are the reciprocals of the roots of \(10x^2 - x - 5 = 0\) is \(5x^2 + x - 10 = 0\). 2. **Statement 2**: To obtain a quadratic equation whose roots are the reciprocals of the roots of the given equation \(ax^2 + bx + c = 0\), change the coefficients \(a, b, c\) to \(c, b, a\) (where \(c \neq 0\)). ### Step-by-Step Solution: #### Step 1: Find the roots of the equation \(10x^2 - x - 5 = 0\). Using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \(a = 10\), \(b = -1\), and \(c = -5\). Calculating the discriminant: \[ D = b^2 - 4ac = (-1)^2 - 4 \cdot 10 \cdot (-5) = 1 + 200 = 201 \] Now, substituting into the quadratic formula: \[ x = \frac{1 \pm \sqrt{201}}{20} \] Let the roots be: \[ \alpha = \frac{1 + \sqrt{201}}{20}, \quad \beta = \frac{1 - \sqrt{201}}{20} \] #### Step 2: Find the reciprocals of the roots. The reciprocals of the roots are: \[ \frac{1}{\alpha} = \frac{20}{1 + \sqrt{201}}, \quad \frac{1}{\beta} = \frac{20}{1 - \sqrt{201}} \] #### Step 3: Form the quadratic equation with these roots. The sum of the reciprocals: \[ \frac{1}{\alpha} + \frac{1}{\beta} = \frac{\beta + \alpha}{\alpha \beta} = \frac{\frac{1 - \sqrt{201}}{20} + \frac{1 + \sqrt{201}}{20}}{\alpha \beta} \] Calculating \(\alpha \beta\): \[ \alpha \beta = \frac{-5}{10} = -\frac{1}{2} \] Thus, \[ \frac{1}{\alpha} + \frac{1}{\beta} = \frac{1/20}{-\frac{1}{2}} = -\frac{1}{10} \] The product of the reciprocals: \[ \frac{1}{\alpha} \cdot \frac{1}{\beta} = \frac{1}{\alpha \beta} = -2 \] Using the sum and product to form the quadratic equation: \[ x^2 - \left(-\frac{1}{10}\right)x - 2 = 0 \implies 10x^2 + x - 20 = 0 \] To match the form \(5x^2 + x - 10 = 0\), divide the entire equation by 2: \[ 5x^2 + x - 10 = 0 \] #### Conclusion for Statement 1: Thus, **Statement 1 is correct**. #### Step 4: Verify Statement 2. To obtain a quadratic equation whose roots are the reciprocals of the roots of \(ax^2 + bx + c = 0\), we replace \(a, b, c\) with \(c, b, a\). This is indeed correct as shown in the derivation above. ### Conclusion for Statement 2: Thus, **Statement 2 is also correct**. ### Final Answer: Both statements are correct.
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