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Rational Leading Term Sign Tool

Determine the rational leading-term sign on a chosen infinite ray from supplied nonzero leading coefficients and degrees.

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Description

Return rational leading sign at a supplied infinity direction.

Local polynomial and rational-function behavior depends on the order of zeros and poles and on the sign of the leading term. Canceling equal local orders differs from evaluating an undefined original expression; a zero placeholder for a pole must be read with its finite/defined flag.

Return rational leading sign at a supplied infinity direction.

When to use this tool

Use Rational Leading Term Sign when checking the stated local order, leading behavior or limit convention.

How to use the tool and how it works

  1. Enter numeratorLeading, denominatorLeading, approachPositiveInfinity, numeratorDegree, denominatorDegree. 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 leadingSign, degreeDifference. Use the output convention below.

Return rational leading sign at a supplied infinity direction. Require nonzero leading coefficients and nonnegative whole degrees; degreeDifference = numerator-denominator, sign combines coefficient signs and negative-infinity parity.1

Input fieldMeaning and unitsAccepted input
numeratorLeadingNumerator LeadingRequired. Finite number.
denominatorLeadingDenominator LeadingRequired. Finite number.
approachPositiveInfinityApproach Positive InfinityRequired. Boolean.
numeratorDegreeNumerator DegreeRequired. Safe integer; minimum 0.
denominatorDegreeDenominator DegreeRequired. Safe integer; minimum 0.
Output fieldInterpretationReturned shape
leadingSignLeading SignRequired. Safe integer.
degreeDifferenceDegree DifferenceRequired. Safe integer.
json
{
  "input": {
    "numeratorLeading": 2,
    "denominatorLeading": -3,
    "approachPositiveInfinity": true,
    "numeratorDegree": 3,
    "denominatorDegree": 1
  },
  "output": {
    "leadingSign": -1,
    "degreeDifference": 2
  }
}

Limitations and assumptions

  • This is the sign of the leading asymptotic term, not necessarily a finite limit or proof that supplied degrees/coefficients describe a valid function.
  • 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 the complete function, original domain and an appropriate symbolic limit or asymptotic analysis for a full mathematical conclusion.

References

  1. Calculation and input contract: algebra/rational-leading-term-sign — tool.io

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