UtilVox
📐
Algebra · Calculus

Quadratic Equation Solver

Solve quadratic equations ax² + bx + c = 0 with comprehensive step-by-step math breakdowns, behavior presets, and real-time interactive plotting.

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⚡ Behavior Presets
3x² + 5x - 2 = 0

Live Equation Preview

3
5
-2
Roots & Discriminant
Discriminant (Δ)
49
Root x₁
0.3333 (1/3)
Root x₂
-2.0000

📈 Curve Properties

Vertex (h, k)(-0.83, -4.08)
Axis of Symmetryx = -0.83
Y-Intercept(0, -2)
DirectionOpens Up ▲

Visual Parabola Plot

Curve Roots
VertexY-Intx₁x₂
Scale: 1 unit = 20px

Detailed Mathematical Solution

Step 1

Equation coefficients: a = 3, b = 5, c = -2

Step 2

Discriminant Δ = b² - 4ac = (5)² - 4(3)(-2)

Step 3

Δ = 25 - (-24) = 49

Step 4

Since Δ > 0, equation has two distinct real roots: x = (-b ± √Δ) / 2a

Step 5

x = (-(5) ± √49) / (2 * 3)

Step 6

x = (-5 ± 7.0000) / 6

Step 7

x₁ = (-5 + 7.0000) / 6 = 0.3333 (1/3)

Step 8

x₂ = (-5 - 7.0000) / 6 = -2.0000

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Understanding Quadratic Equations

A quadratic equation is a second-order algebraic polynomial. The graph of a quadratic equation represents a symmetrical curve known as a parabola.

Standard Quadratic Formula

x = [ -b ± √(b² - 4ac) ] / 2a

What Vertex represents?

The vertex coordinate represents the absolute minimum point (if opens up, where a > 0) or maximum point (if opens down, where a < 0) of the parabola.

Common FAQs

What if the discriminant (Δ) is negative?
When Δ < 0, there are no real roots. Instead, the parabola curve sits entirely above or below the x-axis and has two complex conjugate solutions containing the imaginary unit i.
How is the Axis of Symmetry calculated?
The axis of symmetry represents a vertical mirror line dividing the parabola. Its equation is x = -b / 2a, which corresponds exactly to the x-coordinate of the vertex.
What does y-intercept represent?
The y-intercept represents the point where the curve intersects the vertical axis. It is obtained simply by setting x = 0 in the equation, yielding the value c.

ax² + bx + c, Solved and Explained

The discriminant tells you before you solve

b² − 4ac decides what kind of answer exists:

DiscriminantRootsGraph meaning
PositiveTwo distinct real rootsParabola crosses the x-axis twice
ZeroOne repeated rootParabola touches the axis once
NegativeTwo complex rootsParabola never reaches the axis
Perfect square (and rational a,b,c)Rational rootsIt would have factored nicely

Three methods, one decision rule

Factoring is fastest when it works (integer-friendly roots), completing the square is what derives the vertex form (and the formula itself), and the quadratic formula always works — it's the safety net. Exam strategy: try ten seconds of factoring; if nothing obvious appears, go straight to the formula and bank the time. The solver shows all steps, which is what matric/FSc marking schemes actually award.

Quadratics outside the textbook

Projectile motion (height vs time is a parabola), profit maximization, area-with-fixed-perimeter problems, and the px²-shaped cost curves of physics and economics homework. Geometry-flavored quadratics — right triangles via Pythagoras — get a dedicated treatment in the triangle calculator, and everything else evaluates in the scientific calculator.