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Quadratic Formula Calculator

Solve any quadratic equation ax² + bx + c = 0 for its real or complex roots.

Solve for x in: a·x² + b·x + c = 0

The quadratic formula

For any equation of the form ax² + bx + c = 0, the roots are x = (-b ± √(b²-4ac)) / 2a. The discriminant, b²-4ac, tells you what kind of roots to expect: positive gives two real roots, zero gives one repeated real root, and negative gives a pair of complex conjugate roots.