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Assertion (A) : The equation 8x^(2)+3kx+...

Assertion (A) : The equation `8x^(2)+3kx+2=0` has equal roots than the value of k is `+-(8)/(3)`.
Reason (R ): The equation `ax^(2)+bx+c=0` has equal roots if `D=b^(2)-4ac=0`.

A

Both A and R are true and R is the correct explanation for A.

B

Both A and R are true and R is not correct explanation for A.

C

A is true but R is false

D

A is false but R is true

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to determine the value of \( k \) for which the quadratic equation \( 8x^2 + 3kx + 2 = 0 \) has equal roots. We will use the discriminant condition for equal roots. ### Step-by-Step Solution: 1. **Identify the coefficients**: The given quadratic equation is in the form \( ax^2 + bx + c = 0 \), where: - \( a = 8 \) - \( b = 3k \) - \( c = 2 \) 2. **Use the discriminant condition**: For the quadratic equation to have equal roots, the discriminant \( D \) must be equal to zero. The discriminant is given by: \[ D = b^2 - 4ac \] Substituting the values of \( a \), \( b \), and \( c \): \[ D = (3k)^2 - 4 \cdot 8 \cdot 2 \] 3. **Calculate the discriminant**: \[ D = 9k^2 - 64 \] 4. **Set the discriminant to zero**: For equal roots, we set the discriminant \( D \) to zero: \[ 9k^2 - 64 = 0 \] 5. **Solve for \( k^2 \)**: Rearranging the equation gives: \[ 9k^2 = 64 \] Dividing both sides by 9: \[ k^2 = \frac{64}{9} \] 6. **Take the square root**: Taking the square root of both sides gives: \[ k = \pm \frac{8}{3} \] ### Final Answer: The values of \( k \) for which the equation \( 8x^2 + 3kx + 2 = 0 \) has equal roots are: \[ k = \frac{8}{3} \quad \text{and} \quad k = -\frac{8}{3} \]
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