Quadratic Equation Calculator

Quadratic Equation & Parabola Geometry Calculator

Solve real & complex roots, extract analytical parabolic conic geometry, and reconstruct polynomials from key features

Polynomial Coefficients: a·x² + b·x + c = 0
Curvature (a ≠ 0)
Linear term
y-intercept
Equation Roots (x₁, x₂)
x₁ = 3.000, x₂ = 2.000
Two Distinct Real Roots (Δ > 0)
Factored Form: (x – 3.000)(x – 2.000) = 0
Discriminant (Δ = b² – 4ac) 1.000 (-5)² – 4(1)(6) = 25 – 24
Sum of Roots (Vieta: -b/a) 5.000 x₁ + x₂ = -(-5.0) / 1.0
Product of Roots (Vieta: c/a) 6.000 x₁ · x₂ = 6.0 / 1.0
Completing the Square Form (x – 2.500)² = 0.250 (x + b/(2a))² = (b² – 4ac)/(4a²)
Parabolic Vertex & Extrema Point (h, k)
(2.500, -0.250)
Absolute Global Minimum
Axis of Symmetry: x = 2.500 • Opens Upward
Focus Coordinates (h, k + 1/(4a)) (2.500, 0.000) Focal distance p = 0.250
Directrix Line (y = k – 1/(4a)) y = -0.500 Equidistant guide line
Latus Rectum Length (|1/a|) 1.000 Chord width through focus (4p)
Vertex Standard Form y = (x – 2.500)² – 0.250 y = a(x – h)² + k
y-Intercept Point (0, 6.000) Value evaluated at x = 0
Semi-Latus Rectum (2p = |1/(2a)|) 0.500 Half-width focal parameter
Point Evaluation & Tangent Line Analysis
Evaluate value & tangent line slope
Reconstructed Standard Equation
2x² – 5x – 12 = 0
a = 2.000, b = -5.000, c = -12.000
Function Value at x₀: f(x₀) -14.000 Coordinate: (2.000, -14.000)
Instantaneous Tangent Slope f'(x₀) 3.000 Derivative: 2ax₀ + b
Tangent Line Equation y = 3x – 20 Linear Taylor polynomial at x₀
Normal Line Equation (Perpendicular) y = -0.333x – 13.333 Slope: m_norm = -1 / f'(x₀)