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If sum of the roots is -2 and product of...

If sum of the roots is -2 and product of the roots is `-15`,

A

1. both the roots lie on the right-side of the V-axis

B

2. both the roots lie on the left-side of the Z-axis

C

3. roots lie on both the sides of thq X-axis

D

4. one root is zero and another root is imaginary number.

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The correct Answer is:
To solve the problem, we need to find the quadratic equation whose roots have a sum of -2 and a product of -15. We can use the relationship between the coefficients of a quadratic equation and its roots. ### Step 1: Write the general form of a quadratic equation The general form of a quadratic equation is: \[ ax^2 + bx + c = 0 \] ### Step 2: Use the relationships for the sum and product of roots For a quadratic equation \( ax^2 + bx + c = 0 \): - The sum of the roots \( \alpha + \beta = -\frac{b}{a} \) - The product of the roots \( \alpha \beta = \frac{c}{a} \) Given: - Sum of the roots \( \alpha + \beta = -2 \) - Product of the roots \( \alpha \beta = -15 \) ### Step 3: Set up the equation Assuming \( a = 1 \) (for simplicity), we can set: - \( -b = -2 \) which implies \( b = 2 \) - \( c = -15 \) Thus, the quadratic equation becomes: \[ x^2 + 2x - 15 = 0 \] ### Step 4: Solve the quadratic equation using the quadratic formula The quadratic formula is: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Substituting \( a = 1 \), \( b = 2 \), and \( c = -15 \): \[ x = \frac{-2 \pm \sqrt{2^2 - 4 \cdot 1 \cdot (-15)}}{2 \cdot 1} \] ### Step 5: Calculate the discriminant Calculating the discriminant: \[ b^2 - 4ac = 2^2 - 4 \cdot 1 \cdot (-15) = 4 + 60 = 64 \] ### Step 6: Substitute back into the formula Now substituting back into the quadratic formula: \[ x = \frac{-2 \pm \sqrt{64}}{2} \] \[ x = \frac{-2 \pm 8}{2} \] ### Step 7: Find the roots Calculating the two possible values: 1. \( x_1 = \frac{-2 + 8}{2} = \frac{6}{2} = 3 \) 2. \( x_2 = \frac{-2 - 8}{2} = \frac{-10}{2} = -5 \) Thus, the roots of the equation are \( 3 \) and \( -5 \). ### Conclusion The roots \( 3 \) and \( -5 \) lie on both sides of the x-axis.
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