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If 1/2 is a root of the equation x^2+kx-...

If `1/2` is a root of the equation `x^2+kx-5/4=0,` then find the value of k.

A

`2`

B

`-2`

C

`1/4`

D

`1/2`

Text Solution

Verified by Experts

The correct Answer is:
A
Since `1/2` is a root of the quadratic equation `x^(2)+kx-5/4=0`
Then `(1/2)^(2)+k(1/2)-5/4=0`
`implies 1/4+k/2-5/4=0implies(1+2k-5)/4=0`
`implies 2k-4=0`
`implies 2k=4impliesk=2`
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NCERT EXEMPLAR-QUADRIATIC EQUATIONS-Quadratic Equations
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  2. Which of the following equations has 2 as a root?

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  3. If 1/2 is a root of the equation x^2+kx-5/4=0, then find the value of ...

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  4. Which of the following equations has the sum of its roots as 3? x^2+3x...

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  5. Value(s) of k for which the quadratic equation 2x^(2)-kx+k=0 has equal...

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  6. Which constant must be added and subtracted to solve the quadratic equ...

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  7. What is the nature of roots of the quadratic equation 2x^2-sqrt5x+1=0 ...

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  8. Which of the following equations has two distinct real roots?

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  9. Which of the following equations has no real roots?

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  10. The roots of the equation (x^2+1)^2-x^2=0 are

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  11. State whether the following quadratic equations have two distinct real...

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  12. State whether the following quadratic equations have two distinct real...

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  13. State whether the following quadratic equations have two distinct real...

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  14. State whether the following quadratic equations have two distinct real...

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  15. State whether the following quadratic equations have two distinct real...

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  16. State whether the following quadratic equations have two distinct real...

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  17. State whether the following quadratic equations have two distinct real...

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  18. State whether the following quadratic equations have two distinct real...

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  19. State whether the following quadratic equations have two distinct real...

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  20. State whether the following quadratic equations have two distinct real...

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