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Algebraic Equation Solver (Linear & Quadratic)

Find exact roots for linear and quadratic equations with discriminant analysis.

Quick Answer:Select linear or quadratic. The solver applies the quadratic formula x = (-b ± √(b² - 4ac)) / (2a) to find all roots.
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How to Use the Equation Solver: Linear & Quadratic Roots Calculator

  1. 1Select equation type (Quadratic ax² + bx + c = 0 or Linear ax + b = 0).
  2. 2Enter the numerical coefficients a, b, and c.
  3. 3Read the calculated real or complex conjugate roots x₁ and x₂.
  4. 4Examine the discriminant value (Δ) to understand root multiplicity and stability.

Formula & How It Works

Quadratic Formula & Discriminant Analysis

x = (-b ± √(b² - 4ac)) / 2a; Discriminant Δ = b² - 4ac

Calculates roots algebraically with full support for negative discriminants (complex roots).

Worked Examples

Solving x² - 5x + 6 = 0

Input: a = 1, b = -5, c = 6

Explanation: b² - 4ac = 25 - 24 = 1. Two distinct real roots: (5 ± 1) / 2 = 3 and 2.

Result: Root 1 = 3.0000, Root 2 = 2.0000, Δ = 1

Frequently Asked Questions

What happens when coefficient a is zero in a quadratic equation?▼

If a = 0, the equation degenerates into a linear equation bx + c = 0 with a single solution x = -c/b.

What does a negative discriminant mean?▼

A negative discriminant means the equation has no real solutions; its roots exist in the complex plane as a pair of conjugate imaginary numbers.

How do you find the vertex of a parabola from its coefficients?▼

The x-coordinate of the vertex is located at x = -b / (2a).

Can this solve linear equations?▼

Yes, select 'Linear' mode to solve standard first-degree equations of the form ax + b = 0.

Quick Reference & Conversion Table

Discriminant ΔRoot NatureParabola GeometryExample
Δ > 0Two distinct real rootsCrosses x-axis twicex² - 5x + 6 = 0
Δ = 0One repeated real rootTouches x-axis at vertexx² - 4x + 4 = 0
Δ < 0Two complex conjugate rootsDoes not intersect x-axisx² + 2x + 5 = 0

⚠️ Common Pitfalls to Avoid

  • •Forgetting to rearrange equations into standard form (ax² + bx + c = 0) before identifying coefficients.
  • •Mishandling negative signs when evaluating -b and b².

💡 Practical Real-World Uses

  • •Calculating projectile motion flight times and peak parabolic apexes in physics.
  • •Determining economic break-even points where cost equals revenue curves.
Last reviewed & updated: 2026-11-11
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