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Let `f(x) = x^2+2x+9; x inRR` Find the value of a real constant k for which the...
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If any quadratic polynomial has real one single root the the discriminant of the quadratic equation is 0.
`f(x) = k`
`x^2+2x+9 = k`
`x^2+2x+(9-k) = 0`
Discriminant `(Delta) = 4-4xx1xx(9-k) = 0`
`4-4xx1xx(9-k) = 0`
`k-9 = -1`
`k = 8`
So for exactly one real root the value of k should be 8.
Posted by jeew-m on September 17, 2013 at 12:25 PM (Answer #1)
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