Quadratic Equation Solver
Roots, vertex and discriminant for ax² + bx + c = 0.
How it works
The quadratic formula, x = (-b ± √(b² - 4ac)) / 2a, solves every quadratic there is.
The discriminant b² - 4ac decides the shape of the answer before you finish. Positive gives two real roots and the parabola crosses the axis twice. Zero gives one repeated root and it just touches. Negative gives a complex conjugate pair and it never crosses at all.