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If the roots of 5x^(2)-kx+1=0 are real a...

If the roots of `5x^(2)-kx+1=0` are real and distinct then

A

`-2sqrt(5)ltklt2sqrt(5)`

B

`kgt2sqrt(5)` only

C

`klt-2sqrt(5)` only

D

either `kgt2sqrt(5)" or "klt-2sqrt(5)`

Text Solution

Verified by Experts

The correct Answer is:
D
The roots of `5x^(2)-kx+1=0` are real and distinct.
`:." "(k^(2)-4xx5xx1)ge0impliesk^(2)ge20implieskgesqrt(20)" or "klt-sqrt(20)`
`implieskgt2sqrt(5)" or "klt-2sqrt(5).`
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