Mathematics for IGCSE & O level - Equations (Section 7 - No. 17)

If the discriminant (b²-4ac) of a quadratic equation is negative, what does it tell you about the roots?

The roots are real and distinct.

The roots are real and equal.

The roots are complex (non-real).

There are no roots.

A negative discriminant implies the square root of a negative number, hence complex roots.