Answer: D
As the roots of the equation \(ax^2+bx+c = 0 (a≠ 0) \) are real and equal, then the discriminant:
\(b^2-4ac=0\)
or, \(-4ac=-b^2\)
or, \(c=\cfrac{b^2}{4a}\)
As the roots of the equation \(ax^2+bx+c = 0 (a≠ 0) \) are real and equal, then the discriminant:
\(b^2-4ac=0\)
or, \(-4ac=-b^2\)
or, \(c=\cfrac{b^2}{4a}\)