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Mathematics

Quadratic Formula

Quadratic Formula — ax² + bx + c = 0

x = (−b ± √(b²−4ac)) / 2a

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Variable Legend

a= coefficient of x²b= coefficient of xc= constantΔ= discriminant = b² − 4ac

Quadratic formula

Finds both roots simultaneously.

Discriminant analysis

Determines the nature of roots before solving.

Δ > 0
Δ = 0
Δ < 0

Vieta's formulas

Relationships between roots and coefficients.

Sum of roots
Product of roots

Vertex form

Rewrite in vertex form to find the parabola's turning point.

Vertex
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Pro Tip

Always verify your input values before calculating. For quadratic formula, small input errors can compound and significantly affect the final result.

Difficulty:Intermediate

Did you know?

The quadratic formula was first written in modern algebraic notation by René Descartes in 1637. Before that, mathematicians described the same method in words and geometric diagrams.

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Reviewed May 2026
Used 25K+ times
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