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02 // Visual Math & Finance SolversΔ = b² − 4ac, x₁ + x₂ = −b/a, x₁·x₂ = c/a

Visual Quadratic Discriminant ($\Delta = b^2 - 4ac$) & Root Nature Analyzer

The quadratic discriminant $\Delta = b^2 - 4ac$ determines root multiplicity: $\Delta > 0$ yields two distinct real roots, $\Delta = 0$ yields one repeated real double root at the vertex, and $\Delta < 0$ yields two complex conjugate roots $-\frac{b}{2a} \pm i\frac{\sqrt{|\Delta|}}{2a}$.

Δ = b² − 4ac, x₁ + x₂ = −b/a, x₁·x₂ = c/a

Inputs & Parameters (3)

-4±0.254
-10±0.510
-12±0.512
-10-5510V(2.00, 0.00)r₁=2.00
Discriminant Δ = b² − 4ac
0
1 Repeated Real Root
Roots (Zero Crossings)
x = 2 (Double Root)
Sum = 4 | Product = 4
Vertex (h, k)
(2, 0)
Global Minimum (Opens Up)
Axis & Y-Intercept
x = 2
Y-Intercept = (0, 4)

20-Row Comparison Table

Compare across:
#Curvature (a) Discriminant (Δ = b² − 4ac)Vertex (h, k)Root Nature
01-480(-0.5, 5)2 Real
02-3.572(-0.57, 5.14)2 Real
03-3.2568(-0.62, 5.23)2 Real
04-2.7560(-0.73, 5.45)2 Real
05-2.2552(-0.89, 5.78)2 Real
06-248(-1, 6)2 Real
07-1.540(-1.33, 6.67)2 Real
08-132(-2, 8)2 Real
09-0.7528(-2.67, 9.33)2 Real
10-0.2520(-8, 20)2 Real
110.2512(8, -12)2 Real
120.754(2.67, -1.33)2 Real
131 (Current)0(2, 0)1 Real
141.5-8(1.33, 1.33)2 Complex
152-16(1, 2)2 Complex
162.25-20(0.89, 2.22)2 Complex
172.75-28(0.73, 2.55)2 Complex
183.25-36(0.62, 2.77)2 Complex
193.5-40(0.57, 2.86)2 Complex
204-48(0.5, 3)2 Complex
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Key Analytical Takeaways

  • 01At default $a=1, b=-4, c=4$, the discriminant is $\Delta = (-4)^2 - 4(1)(4) = 0$, placing the vertex tangentially on the x-axis at $x = 2$.
  • 02Increasing $c$ above $4$ pushes $\Delta < 0$, lifting the parabola above the x-axis and displaying the exact complex conjugate pair $u \pm vi$.
  • 03By Vieta's Formulas, the sum of the two roots is always $-b/a$ and their product is always $c/a$.

Frequently Asked Questions

Why does a negative discriminant produce complex conjugate roots?+

When b² − 4ac < 0, taking the square root √(b² − 4ac) involves the imaginary unit i = √(−1), producing a symmetric pair of complex roots u + vi and u − vi.

What are Vieta's Formulas for a quadratic?+

Without even solving for the roots x₁ and x₂, their sum is guaranteed to be x₁ + x₂ = −b/a and their product is x₁·x₂ = c/a.

What are Vieta's formulas for a quadratic equation?+

Without computing radicals, Vieta's formulas relate the two roots directly to coefficients: their sum is x₁ + x₂ = −b / a and their product is x₁ · x₂ = c / a.