If the quadratic equation \(ax^2+bx+c=0\) has no real roots, what is the correct condition for the discriminant \(D=b^2-4ac\)?

Correct answer: \(D<0\)

For a quadratic equation, the discriminant is \(D=b^2-4ac\). If \(D<0\), then \(\sqrt{D}\) is not real, so the equation has no real roots. When \(D=0\), there are two equal real roots, while \(D>0\) gives two distinct real roots. Exam tip: remember that real roots require \(D\geq0\), whereas no real roots require \(D<0\).