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If a x^2+b x+c=0 has equal roots, then c...

If `a x^2+b x+c=0` has equal roots, then `c=` `-b/(2a)` (b) `b/(2a)` (c) `(-b^2)/(4a)` (d) `(b^2)/(4a)`

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If `ax^2+bx+c=0` has equal root then
`B^2-4AC=0`here`A=a,B=b,C=c`
`b^2-4ac=0=>4ac=b^2`
`C=(b^2)/(4a)`
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