METHOD
Formula and method
D=b²−4ac; x=(−b±√D)/(2a). Real roots use a numerically stable equivalent.
Quadratic equation calculator for ax² + bx + c = 0
Solve ax² + bx + c = 0, including complex and linear cases.
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Full disclaimerHow do you solve a quadratic equation?
The calculator solves a quadratic equation of the form ax² + bx + c = 0. It first computes the discriminant D = b² − 4ac: a positive D gives two real roots, zero gives two equal roots and a negative D gives a pair of complex conjugate roots. If a = 0, it solves the linear equation instead. For a = 1, b = −5 and c = 6 you get D = 1, x₁ = 3 and x₂ = 2, a quick way for pupils and students to check homework.
TRACEABLE
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Basic arithmetic or geometry using the formula shown. Uses only your inputs.
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