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Question 26357: An Exact Closed-Interval Root Witness Does Not Assert Uniqueness

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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← Question derivation index · Original question batch

R0051-26357 · q-20261015-advance-20261116-r02-intermediate-value-theorem-0032

Original question and givens

Coefficients=[6, 1] are in ascending power order, with exact rationals and trailing zero coefficients removed for degree. Use a=-7<b=-5 and target=0 on the whole closed interval. Polynomial continuity and an inclusive endpoint-value bracket are separate hypotheses. Supplied exact root=-6. Give (root, value_at_root, inside_closed_interval, hits_target, uniqueness_or_closed_form_claim, certificate).

  • G001 — Coefficients=[6, 1] are in ascending power order, with exact rationals and trailing zero coefficients removed for degree. Use a=-7<b=-5 and target=0 on the whole closed interval. Polynomial continuity and an inclusive endpoint-value bracket are separate hypotheses. Supplied exact root=-6. Give (root, value_at_root, inside_closed_interval, hits_target, uniqueness_or_closed_form_claim, certificate).

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

source roles = [ivt-exact-root]

After

derived = [[root, value_at_root, inside_closed_interval, hits_target, uniqueness_or_closed_form_claim, certificate]]

Conditions: none

List the full source field order without JavaScript.Original modes select contract6/4/6/6 and IVT8/7/8 roles,without padding or answer-shape inference.

Step identifiers and dependencies

Rule: source_ordered_fields_without_JS · Uses: G001

S002 · implies

Before

(-7)^0

After

IVT ORIGINAL left endpoint ORIGINAL argument power0 = 1

Conditions: none

Evaluate the finite nonnegative-integer power exactly; exponent0 uses the polynomial multiplicative identity.

Step identifiers and dependencies

Rule: integer_power · Uses: G001, S001

S003 · calculation

Before

IVT ORIGINAL left endpoint coefficient term0 := mul(6, 1)

After

IVT ORIGINAL left endpoint coefficient term0 = 6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

IVT ORIGINAL left endpoint ascending partial sum0 := sum(0, 6)

After

IVT ORIGINAL left endpoint ascending partial sum0 = 6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · implies

Before

(-7)^1

After

IVT ORIGINAL left endpoint ORIGINAL argument power1 = -7

Conditions: none

Evaluate the finite nonnegative-integer power exactly; exponent0 uses the polynomial multiplicative identity.

Step identifiers and dependencies

Rule: integer_power · Uses: G001, S004

S006 · calculation

Before

IVT ORIGINAL left endpoint coefficient term1 := mul(1, -7)

After

IVT ORIGINAL left endpoint coefficient term1 = -7

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

IVT ORIGINAL left endpoint ascending partial sum1 := sum(6, -7)

After

IVT ORIGINAL left endpoint ascending partial sum1 = -1

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · implies

Before

(-5)^0

After

IVT ORIGINAL right endpoint ORIGINAL argument power0 = 1

Conditions: none

Evaluate the finite nonnegative-integer power exactly; exponent0 uses the polynomial multiplicative identity.

Step identifiers and dependencies

Rule: integer_power · Uses: G001, S007

S009 · calculation

Before

IVT ORIGINAL right endpoint coefficient term0 := mul(6, 1)

After

IVT ORIGINAL right endpoint coefficient term0 = 6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

IVT ORIGINAL right endpoint ascending partial sum0 := sum(0, 6)

After

IVT ORIGINAL right endpoint ascending partial sum0 = 6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

(-5)^1

After

IVT ORIGINAL right endpoint ORIGINAL argument power1 = -5

Conditions: none

Evaluate the finite nonnegative-integer power exactly; exponent0 uses the polynomial multiplicative identity.

Step identifiers and dependencies

Rule: integer_power · Uses: G001, S010

S012 · calculation

Before

IVT ORIGINAL right endpoint coefficient term1 := mul(1, -5)

After

IVT ORIGINAL right endpoint coefficient term1 = -5

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

IVT ORIGINAL right endpoint ascending partial sum1 := sum(6, -5)

After

IVT ORIGINAL right endpoint ascending partial sum1 = 1

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · implies

Before

source roles = [[6, 1], -7, -5, 0]

After

derived = [-1, 1, Yes, Yes]

Conditions: none

Every monomial and finite polynomial sum is continuous on the whole interval,not by sampled agreement.Target bracketing allows increasing or decreasing endpoint values and equality;qualification may report bracketFalse.

Step identifiers and dependencies

Rule: IVT_WHOLE_polynomial_continuity_inclusive_both_endpoint_orientations · Uses: G001, S013

S015 · implies

Before

(-6)^0

After

IVT ORIGINAL supplied root ORIGINAL argument power0 = 1

Conditions: none

Evaluate the finite nonnegative-integer power exactly; exponent0 uses the polynomial multiplicative identity.

Step identifiers and dependencies

Rule: integer_power · Uses: G001, S014

S016 · calculation

Before

IVT ORIGINAL supplied root coefficient term0 := mul(6, 1)

After

IVT ORIGINAL supplied root coefficient term0 = 6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S015

S017 · calculation

Before

IVT ORIGINAL supplied root ascending partial sum0 := sum(0, 6)

After

IVT ORIGINAL supplied root ascending partial sum0 = 6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · implies

Before

(-6)^1

After

IVT ORIGINAL supplied root ORIGINAL argument power1 = -6

Conditions: none

Evaluate the finite nonnegative-integer power exactly; exponent0 uses the polynomial multiplicative identity.

Step identifiers and dependencies

Rule: integer_power · Uses: G001, S017

S019 · calculation

Before

IVT ORIGINAL supplied root coefficient term1 := mul(1, -6)

After

IVT ORIGINAL supplied root coefficient term1 = -6

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · calculation

Before

IVT ORIGINAL supplied root ascending partial sum1 := sum(6, -6)

After

IVT ORIGINAL supplied root ascending partial sum1 = 0

Conditions: none

Substitute original roles and established intermediates exactly,without rounding;extra teaching identities do not restrict the source domain.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S019

S021 · implies

Before

source roles = [-7, -5, 0, -6]

After

derived = [0, Yes, Yes, No, No]

Conditions: none

Check the supplied exact root value and closed-interval membership.An endpoint-family witness may be interior,with flagFalse.The fixed No on exact-root withholds general uniqueness/rational closed-form guarantees,not this witness.

Step identifiers and dependencies

Rule: IVT_actual_closed_interval_root_hit_endpoint_flag_separate · Uses: G001, S020

Reverse checks

  • S021 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S020 · premise_and_result_audit — Recompute IVT ORIGINAL supplied root ascending partial sum1 with exact rational arithmetic, not rounded decimals.
  • S019 · premise_and_result_audit — Recompute IVT ORIGINAL supplied root coefficient term1 with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S017 · premise_and_result_audit — Recompute IVT ORIGINAL supplied root ascending partial sum0 with exact rational arithmetic, not rounded decimals.
  • S016 · premise_and_result_audit — Recompute IVT ORIGINAL supplied root coefficient term0 with exact rational arithmetic, not rounded decimals.
  • S015 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S014 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S013 · premise_and_result_audit — Recompute IVT ORIGINAL right endpoint ascending partial sum1 with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute IVT ORIGINAL right endpoint coefficient term1 with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S010 · premise_and_result_audit — Recompute IVT ORIGINAL right endpoint ascending partial sum0 with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute IVT ORIGINAL right endpoint coefficient term0 with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S007 · premise_and_result_audit — Recompute IVT ORIGINAL left endpoint ascending partial sum1 with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute IVT ORIGINAL left endpoint coefficient term1 with exact rational arithmetic, not rounded decimals.
  • 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 IVT ORIGINAL left endpoint ascending partial sum0 with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute IVT ORIGINAL left endpoint coefficient term0 with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.

Result

(-6, 0, Yes, Yes, No, IVT_existence_does_not_imply_uniqueness_or_rational_closed_form)

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: 390d61f6146a1002dcca6ceaa05658ef6bff1aca14dc7e61584eec68776e22d7
  • candidate record SHA-256: 546298c9050a47418e4011cc5db406d12517cdf4ae6f132c9ca8e0a695a318e3
  • semantic review receipt SHA-256: 90df1e889242e9afdf01e068788ee8500ef366ffcfc0496e30a6800de32631c3
  • question-first witness SHA-256: ae1e849608590ca856c9f3b6911ba58e3bf53c608eb7369606192a770f48bd5c
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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