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Question
If the equation `x^2-5x+1=0` has no real roots then
(a)`k<-2`
(b)`k>2`
(c) `-2<k<2`
(d) None of these
Solution
It is given that the equation `x^2-kx+1=0` has no real roots.
∴ `(b^2-4ac)<0`
⇒`(-k)^2-4xx1xx<0`
⇒` k^2<4`
⇒`-2<k<2`
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