Explore related knowledge and questions →

Question 34613: Exact Substitution of a Rational Root Candidate

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

Return to catalogue page 174

← Question derivation index · Original question batch

R0068-34613 · q-20261003-r04-quadratic-equation-0063

Original question and givens

Over the reals, (2)x²+(0)x+(0)=0 has a≠0. Is the reduced rational candidate x=0/1, with positive denominator, a solution?

  • G001 — Over the reals, (2)x²+(0)x+(0)=0 has a≠0. Is the reduced rational candidate x=0/1, with positive denominator, a solution?

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 = [qf-quadratic-root-verification, [a, b, c, domain, operation, p, q]]

After

derived = [root_verification, reals]

Conditions: none

Separate source banks:legacy RAW SAFE with unbounded derived BigInts versus BASE Number.isInteger without invented SAFE/million caps.Operations,domains and permissive/exact keys follow THIS bank.Keep ORIGINAL JSON intact.

Step identifiers and dependencies

Rule: R68_BANK_specific_keys_operations_and_numeric_guards · Uses: G001

S002 · implies

Before

source roles = [2, 0, 0, 0, 1]

After

derived = [0/1, Yes]

Conditions: none

FIRST qualify a≠0 and an ALREADY reduced candidate with POSITIVE denominator.Zero can only be0/1.This task checks THIS candidate;No is legal and does not require a nonnegative or square discriminant.

Step identifiers and dependencies

Rule: Quadratic_ROOT_candidate_ALREADY_reduced_positive_DEN · Uses: G001, S001

S003 · calculation

Before

Root verification SOURCE unused discriminant b squared := mul(0, 0)

After

Root verification SOURCE unused discriminant b squared = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

Root verification SOURCE discriminant ORIGINAL a times c := mul(2, 0)

After

Root verification SOURCE discriminant ORIGINAL a times c = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

Root verification SOURCE unused discriminant four a c := mul(4, 0)

After

Root verification SOURCE unused discriminant four a c = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Root verification SOURCE unused signed discriminant := sub(0, 0)

After

Root verification SOURCE unused signed discriminant = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

Root verification ORIGINAL candidate numerator squared := mul(0, 0)

After

Root verification ORIGINAL candidate numerator squared = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

Root verification ORIGINAL candidate denominator squared := mul(1, 1)

After

Root verification ORIGINAL candidate denominator squared = 1

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

Root verification ORIGINAL a times numerator squared := mul(2, 0)

After

Root verification ORIGINAL a times numerator squared = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

Root verification ORIGINAL b times candidate numerator := mul(0, 0)

After

Root verification ORIGINAL b times candidate numerator = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

Root verification ORIGINAL b numerator denominator := mul(0, 1)

After

Root verification ORIGINAL b numerator denominator = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · calculation

Before

Root verification ORIGINAL c times denominator squared := mul(0, 1)

After

Root verification ORIGINAL c times denominator squared = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

Root verification ORIGINAL all denominator-cleared terms := sum(0, 0, 0)

After

Root verification ORIGINAL all denominator-cleared terms = 0

Conditions: none

Calculate exactly from ORIGINAL ordered operands;mul/sub/div have EXPLICITLY TWO operands.Legacy derived BigInts are not recapped at RAW SAFE;check BASE Number type/representation conditions separately.Do not use floating approximations to force an answer.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · implies

Before

source roles = [2, 0, 0, 0, 1, 0]

After

derived = [0, Yes]

Conditions: none

Substitute x=p/q into the ORIGINAL equation and multiply by NONZERO q².This is equivalent to a*p²+b*p*q+c*q²=0.Retain ALL three terms,including zeros.The SOURCE computes D but this family does not gate its sign/squareness or infer the complete root set.

Step identifiers and dependencies

Rule: Quadratic_ROOT_clear_NONzero_denominator_ALL_three_terms · Uses: G001, S013

Reverse checks

  • S014 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S013 · premise_and_result_audit — Recompute Root verification ORIGINAL all denominator-cleared terms with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute Root verification ORIGINAL c times denominator squared with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute Root verification ORIGINAL b numerator denominator with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute Root verification ORIGINAL b times candidate numerator with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute Root verification ORIGINAL a times numerator squared with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute Root verification ORIGINAL candidate denominator squared with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute Root verification ORIGINAL candidate numerator squared with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Root verification SOURCE unused signed discriminant with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Root verification SOURCE unused discriminant four a c with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Root verification SOURCE discriminant ORIGINAL a times c with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute Root verification SOURCE unused discriminant b squared with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.
  • S001 · premise_and_result_audit — Reverse-check THIS question’s ORIGINAL givens,domain and step premises.Preserve originals/English/MKOs/ASTs/status;do not reverse a one-way implication or call finite checks independent review or general formal proof.

Result

Yes

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: c8221899a7438c78cf40160f44d8f1d77c11ea2220da7be5ef7e3eb9ea1281ab
  • candidate record SHA-256: 94fbe9ad128d7a6f12c427328125f9c705ddfbf2a3f64aa345021f4f0cd03bca
  • semantic review receipt SHA-256: e7a54104fa02c235f7591329bd6db8d626dd74bf0fae29c557b1f269c85066ed
  • question-first witness SHA-256: 8401a3c2064c1275a6a7ea8f00412fa12286cec7b2db6c305ff9dba3724ae229
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON