Quadratic Formula Calculator — Solve ax² + bx + c = 0

Solve any quadratic equation with the quadratic formula. Find both roots, discriminant, vertex, axis of symmetry, and factored form with step-by-step solutions.

Quadratic Formula Calculator

Leading coefficient (a ≠ 0)
Root x₁
3.0000
First solution
Root x₂
2.0000
Second solution
Discriminant (Δ)
1.0000
Two distinct real roots
Vertex
(2.5000, -0.2500)
Parabola opens up (minimum)
Axis of Symmetry
x = 2.5000
Vertical line through vertex
y-Intercept
6.0000
Value at x = 0
Sum of Roots
5.0000
−b/a (Vieta's formula)
Product of Roots
6.0000
c/a (Vieta's formula)
Factored Form
(x − 3)(x − 2)
Integer factors
Two distinct real roots — Δ = 1.00

Parabola Properties

Opens
Upward ↑
Vertex x
2.50
Vertex y
-0.25
Steepness |a|
1.00

Step-by-Step Solution

StepComputation
Equation1x² + (-5)x + 6 = 0
Identify a, b, ca = 1, b = -5, c = 6
Discriminant (b²−4ac)(-5)² − 4(1)(6) = 25 − 24 = 1
√|Δ|1.0000
−b / 2a2.5000
x₁3.0000
x₂2.0000

Discriminant Reference

ConditionRoot TypeExample
Δ > 0Two distinct real rootsx²−5x+6=0 → x=2, x=3
Δ = 0One repeated real rootx²−4x+4=0 → x=2
Δ < 0Two complex conjugate rootsx²+1=0 → x=±i
Planning notes, formulas, and examples

About the Quadratic Formula Calculator — Solve ax² + bx + c = 0

The quadratic formula is one of the most important tools in algebra: x = (−b ± √(b² − 4ac)) / 2a. It provides an exact solution for any equation of the form ax² + bx + c = 0, regardless of whether the roots are real, repeated, or complex. Our quadratic formula calculator lets you enter coefficients a, b, and c, then displays both roots, the discriminant value, vertex coordinates, axis of symmetry, y-intercept, and factored form when integer factors exist.

Understanding the discriminant (Δ = b² − 4ac) is key to predicting the nature of the solutions before you even compute them. When Δ > 0 you get two distinct real roots, when Δ = 0 you get one repeated root, and when Δ < 0 the roots are complex conjugates. This calculator color-codes the result so you can immediately see which case applies.

Beyond finding roots, the calculator reports parabola properties: whether the curve opens upward or downward, the minimum or maximum vertex point, and the steepness determined by the leading coefficient. A step-by-step solution table walks through each computation so students can follow the algebra and verify their own work. Eight common equation presets let you load classic textbook problems for quick exploration.

When This Page Helps

Quadratic Formula Calculator — Solve ax² + bx + c = 0 helps you solve quadratic formula calculator — solve ax² + bx + c = 0 problems quickly while keeping each step transparent. Instead of redoing long algebra by hand, you can enter Coefficient a, Coefficient b, Coefficient c once and immediately inspect Root x₁, Root x₂, Discriminant (Δ) to validate your work.

How to Use the Inputs

  1. Enter Coefficient a and Coefficient b in the input fields.
  2. Select the mode, method, or precision options that match your quadratic formula calculator — solve ax² + bx + c = 0 problem.
  3. Read Root x₁ first, then use Root x₂ to confirm your setup is correct.
  4. Try a preset such as "x²−5x+6=0" to test a known case quickly.
Formula used
x = (−b ± √(b² − 4ac)) / 2a, where Δ = b² − 4ac is the discriminant. Vertex at (−b/2a, f(−b/2a)). Sum of roots = −b/a. Product of roots = c/a.

Example Calculation

Result: Root x₁ shown by the calculator

Using the preset "x²−5x+6=0", the calculator evaluates the quadratic formula calculator — solve ax² + bx + c = 0 setup, applies the selected algebra rules, and reports Root x₁ with supporting checks so you can verify each transformation.

Tips & Best Practices

  • If a = 0 the equation is linear, not quadratic — divide by x or use simple algebra.
  • A negative discriminant means the parabola never crosses the x-axis.
  • The vertex is always the midpoint between the two roots.
  • Multiply the whole equation by −1 to flip the sign of a if visualising helps.
  • Use the factored form to verify: expand (x − r₁)(x − r₂) and check it matches.

How This Quadratic Formula Calculator — Solve ax² + bx + c = 0 Works

This calculator takes Coefficient a, Coefficient b, Coefficient c and applies the relevant quadratic formula calculator — solve ax² + bx + c = 0 relationships from your chosen method. It returns both final and intermediate values so you can audit the process instead of treating it as a black box.

Interpreting Results

Start with the primary output, then use Root x₁, Root x₂, Discriminant (Δ), Vertex to confirm signs, magnitude, and internal consistency. If anything looks off, change one input and compare the updated outputs to isolate the issue quickly.

Study Strategy

Sources & Methodology

Last updated:

Frequently Asked Questions

  • It is x = (−b ± √(b² − 4ac)) / 2a, used to solve any second-degree polynomial equation ax² + bx + c = 0.