Quadratic Equation Solver

It is b² − 4ac. If positive there are two real roots, if zero one repeated root, if negative two complex roots.

If a = 0 the equation is linear, not quadratic, and the quadratic formula does not apply. Our tool will warn you.

The vertex is the turning point of the parabola, found at x = −b/2a. It is a minimum when a > 0 and a maximum when a < 0.

Plug each root back into ax² + bx + c. The result should be (very close to) zero.