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प्रश्न
If the equation `x^2+5kx+16=0` has no real roots then
(a)`k>8/5` (b) `k(-8)/5`
(c)` (-8)/5<k<8/5` (d) None Of these
उत्तर
(c) `(-8)/5<k<8/5`
It is given that the equation `(x^+5kx+16=0)` has no real roots.
∴`(b^2-4ac)<`
⇒`(5k)^2-4xx1xx16<0`
⇒`25k^2-64<0`
⇒`k^2<64/25`
⇒`-8/5<k<8/5`
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