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Question 3836: Integer Endpoint Recovered from a Nonzero Constant Integral

On this page
  1. Original question and givens
  2. Definition and scope
  3. Step-by-step derivation
  4. Reverse checks
  5. Result
  6. This question review and source binding

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R0006-03836 · q-20261007-advance-20261009-r06-definite-integral-0086

Original question and givens

On all R, the constant integrand is c=11≠0. Starting at a=-2, its oriented integral has target 242/2. Recover b, which is promised to remain an integer endpoint in this slice. Use reduced positive-denominator fractions, retaining /1 for integers.

  • G001 — On all R, the constant integrand is c=11≠0. Starting at a=-2, its oriented integral has target 242/2. Recover b, which is promised to remain an integer endpoint in this slice. Use reduced positive-denominator fractions, retaining /1 for integers.

Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.

Step-by-step derivation

S001 · implies

Before

explicit real polynomial moment or constant integrand model

After

oriented I(a,b)=H(b)−H(a);do not sort endpoints

Conditions: none

Real polynomials are continuous and integrable;use termwise primitive endpoint differences for exact oriented integrals,not absolute area or a finite sum.

Step identifiers and dependencies

Rule: polynomial_moment_scope · Uses: G001

S002 · calculation

Before

oriented interval displacement := div(121, 11)

After

oriented interval displacement = 11

Conditions: none

Divide c(b−a)=target by nonzero c,without absolute values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

recovered endpoint := sum(-2, 11)

After

recovered endpoint = 9

Conditions: none

Add the oriented displacement to a;this frozen exercise slice requires an integer endpoint.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

endpoint reverse substitution := mul(11, 11)

After

endpoint reverse substitution = 121

Conditions: none

Substitute into c(b−a) to audit the target;target0 gives b=a.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

c=11≠0;b=9

After

I(a,b)=121=target

Conditions: none

A nonzero constant makes the endpoint unique;negative c or target does not permit arbitrary endpoint reordering.

Step identifiers and dependencies

Rule: unique_constant_endpoint · Uses: G001, S004

Reverse checks

  • S005 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S004 · premise_and_result_audit — Recompute endpoint reverse substitution with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute recovered endpoint with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute oriented interval displacement with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.

Result

9/1

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.

This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.

Source hashes and review receipts
  • input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
  • original question SHA-256: 06897b526f29f0d8bd01af9ae985f4aca5eae29fbe6bd2d5e5ecd89975d654af
  • candidate record SHA-256: b583e06d5358d270cc24295f4874200826a274340617f2595b10322293e235a4
  • semantic review receipt SHA-256: 568eefd71709ac3dc16a0d5b3b4ad3e83376a8ef300c9e5493eee0721500b29d
  • question-first witness SHA-256: d964b91bedb9d4918bbc055f567762a09f5a58af6c876268e719d5100332d855
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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