Round #997
19 May 2026, 09:52· math· Meta-Llama-3.3-70B-Instruct· r13-clean-hints
- Complexity
- band 0
- ZP / UO / OBS
- 3 / 0 / 2
- Journey weight
- 405
- Lightshift ΔL
- —
Prompt
State the quadratic formula for solving ax^2 + bx + c = 0 and show how to use it to solve 2x^2 + 5x - 3 = 0.
Zero-point index (what the engine surfaced)
ZPI-ZPI-0001 | 2026-05-19T09:52:24Z
State the quadratic formula for solving ax^2 + bx + c = 0 and show how to use it to solve 2x^2 + 5x - 3 = 0.
ZERO POINT — 3 entries (structural invariants)
● hsl(5.66, 100%, 15%) quadratic formula x = (-b ± √(b²-4ac))/(2a) [contract]
● hsl(88.73, 100%, 15%) discriminant b²-4ac [contract]
● hsl(244.41, 100%, 15%) two-root structure [contract]
UNOBSERVED — 0 entries (implied truths)
OBSERVED — 2 entries (explicit in request)
◉ hsl(148.72, 100%, 22%) + [feature]
◉ hsl(175.38, 100%, 27%) = [feature]
COMPLEXITY │ 5 entries │ spread: 27° │ band: LOW
Baseline response (no ZPI)
```csharp
using System;
class Program
{
static void Main()
{
// define the coefficients
double a = 2;
double b = 5;
double c = -3;
// calculate the discriminant
double discriminant = b * b - 4 * a * c;
// calculate the two roots
double root1 = (-b + Math.Sqrt(discriminant)) / (2 * a);
double root2 = (-b - Math.Sqrt(discriminant)) / (2 * a);
Console.WriteLine("The roots of the equation are: " + root1 + " and " + root2);
}
}
```
Enhanced response (with ZPI)
The quadratic formula for solving ax^2 + bx + c = 0 is x = (-b ± √(b²-4ac))/(2a).
To solve 2x^2 + 5x - 3 = 0 using this formula, we first identify the coefficients: a = 2, b = 5, and c = -3.
Then, we calculate the discriminant: b² - 4ac = 5² - 4*2*(-3) = 25 + 24 = 49.
Next, we plug these values into the quadratic formula:
x = (-5 ± √49)/(2*2)
x = (-5 ± 7)/4
This gives us two roots:
x = (-5 + 7)/4 = 2/4 = 1/2
x = (-5 - 7)/4 = -12/4 = -3
So, the solutions to the equation 2x^2 + 5x - 3 = 0 are x = 1/2 and x = -3.
Here is a C# implementation of the quadratic formula:
```csharp
using System;
public class QuadraticSolver
{
public static (double, double) SolveQuadratic(double a, double b, double c)
{
double discriminant = b * b - 4 * a * c;
if (discriminant < 0)
{
throw new InvalidOperationException("The equation has no real solutions.");
}
double sqrtDiscriminant = Math.Sqrt(discriminant);
double root1 = (-b + sqrtDiscriminant) / (2 * a);
double root2 = (-b - sqrtDiscriminant) / (2 * a);
return (root1, root2);
}
public static void Main(string[] args)
{
double a = 2;
double b = 5;
double c = -3;
try
{
var (root1, root2) = SolveQuadratic(a, b, c);
Console.WriteLine($"The solutions to the equation {a}x^2 + {b}x + {c} = 0 are x = {root1} and x = {root2}.");
}
catch (InvalidOperationException ex)
{
Console.WriteLine(ex.Message);
}
}
}
```
Grader chain
Each grader reads the same baseline + enhanced pair and casts an independent verdict. Disagreement is the framework's own signal — not noise to be averaged away.
V1samba/Meta-Llama-3.3-70B-Instruct
BetterV4qwen2.5-coder-3b-instruct
BetterV5cerebras/qwen-3-235b-a22b-instruct-2507
BetterV7qwen2.5-coder-7b-instruct
BetterV8openai/gpt-4.1
BetterV9anthropic/claude-opus-4-7
BetterV12openai/gpt-4o
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