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Quadratic Completing Square Offset Tool

Calculate quadratic completing square offset from explicit caller-supplied inputs.

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Description

Return completing-square shift and vertical offset.

Polynomial coefficients encode powers in a chosen order, with zeros, multiplicities and leading terms carrying different meanings. Local coefficient identities and necessary divisibility conditions can be checked without finding every root or proving a proposed factorization. Floating-point comparisons use the exact supplied values unless an explicit tolerance is provided.

Return completing-square shift and vertical offset.

When to use this tool

Use Quadratic Completing Square Offset when checking the stated coefficient, root-identity, index or divisibility term.

How to use the tool and how it works

  1. Enter a, b, c. Use the units and conventions below.
  2. Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
  3. Read shift, offset. Use the output convention below.

Return completing-square shift and vertical offset. Require a != 0; shift = b/(2*a), offset = c-b²/(4*a).1

Input fieldMeaning and unitsAccepted input
aARequired. Finite number.
bBRequired. Finite number.
cCRequired. Finite number.
Output fieldInterpretationReturned shape
shiftPositive b/(2*a) in a*(x+shift)^2+offset; vertex x is -shift.Required. Finite number.
offsetOffsetRequired. Finite number.
json
{
  "input": {
    "a": 2,
    "b": 8,
    "c": 3
  },
  "output": {
    "shift": 2,
    "offset": -5
  }
}

Limitations and assumptions

  • The rewritten form is a*(x+shift)²+offset, so vertex x is -shift; no symbolic derivation or numerical-error guarantee is produced.
  • Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
  • Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Use a complete symbolic or numerically appropriate polynomial method for root finding, full factorization and robust treatment of near-degenerate coefficients.

References

  1. Calculation and input contract: algebra/quadratic-completing-square-offset — tool.io

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