What Discriminant Is Negative?

A positive discriminant indicates that the quadratic has two distinct real number solutions. A discriminant of zero indicates that the quadratic has a repeated real number solution. A negative discriminant indicates that neither of the solutions are real numbers.

How do you know if a discriminant is negative?

The discriminant is the term underneath the square root in the quadratic formula and tells us the number of solutions to a quadratic equation. If the discriminant is positive, we know that we have 2 solutions. If it is negative, there are no solutions and if the discriminant is equal to zero, we have one solution.

What does a negative discriminant always have?

A negative discriminant means that the parabola has no real roots (only imaginary roots.) Roots are where the parabola crosses the x-intercept and we know the parabola has no real roots, so it must never touch the x-axis. This means that the graph will have no x-intercept.

Robert Thorne

Robert Thorne

Automotive & Future Transportation Editor

Robert Thorne covers electric vehicle innovations, autonomous driving systems, global mobility trends, and automotive engineering developments.