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If x^2+4ax+2 gt 0 for all values of x, t...

If `x^2+4ax+2 gt 0` for all values of x, then a lies in the interval a)(-2,4) b)(1,2) c)`(-sqrt2,sqrt2)` d)`(-1/sqrt2,1/sqrt2)`

A

(-2,4)

B

(1,2)

C

`(-sqrt2,sqrt2)`

D

`(-1/sqrt2,1/sqrt2)`

Text Solution

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The correct Answer is:
D
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