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Question 1943: Candidate Value and Derivative against Two Initial Conditions

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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R0002-01943 · q-20261013-advance-20261020-r02-ordinary-differential-equation-0093

Original question and givens

The integer-coefficient polynomial candidate has ascending-power coefficients=[8, 0, 2]. Exact checks concern only the specified point or initial conditions, not existence, uniqueness or a solution on an entire interval. x0=0, required y0=8, required y'0=0. Give (coefficients, x0, actual y, actual y', required y0, required y'0, first condition?, second condition?, both?).

  • G001 — The integer-coefficient polynomial candidate has ascending-power coefficients=[8, 0, 2]. Exact checks concern only the specified point or initial conditions, not existence, uniqueness or a solution on an entire interval. x0=0, required y0=8, required y'0=0. Give (coefficients, x0, actual y, actual y', required y0, required y'0, first condition?, second condition?, both?).

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

candidate y ascending coefficients=[8, 0, 2]

After

audit point x=0

Conditions: none

Retain the original coefficient list,including top zero terms,and audit only the specified polynomial candidate and point.

Step identifiers and dependencies

Rule: polynomial_candidate_domain · Uses: G001

S002 · calculation

Before

y′ coefficient at degree0 := mul(1, 0)

After

y′ coefficient at degree0 = 0

Conditions: none

Multiply by the original degree and lower it by1;the constant term differentiates to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

y′ coefficient at degree1 := mul(2, 2)

After

y′ coefficient at degree1 = 4

Conditions: none

Multiply by the original degree and lower it by1;the constant term differentiates to0.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · implies

Before

y ascending coefficients=[8, 0, 2]

After

evaluate at x=0

Conditions: none

Evaluate ascending coefficients by Horner from the highest nonzero term down;ignoring redundant top zero terms changes neither the function nor the retained original list.

Step identifiers and dependencies

Rule: polynomial_evaluation_order · Uses: G001, S003

S005 · calculation

Before

y Horner multiply before degree1 := mul(2, 0)

After

y Horner multiply before degree1 = 0

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

y Horner add degree1 := sum(0, 0)

After

y Horner add degree1 = 0

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

y Horner multiply before degree0 := mul(0, 0)

After

y Horner multiply before degree0 = 0

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

y Horner add degree0 := sum(0, 8)

After

y Horner add degree0 = 8

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · implies

Before

y′ ascending coefficients=[0, 4]

After

evaluate at x=0

Conditions: none

Evaluate ascending coefficients by Horner from the highest nonzero term down;ignoring redundant top zero terms changes neither the function nor the retained original list.

Step identifiers and dependencies

Rule: polynomial_evaluation_order · Uses: G001, S008

S010 · calculation

Before

y′ Horner multiply before degree0 := mul(4, 0)

After

y′ Horner multiply before degree0 = 0

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

y′ Horner add degree0 := sum(0, 0)

After

y′ Horner add degree0 = 0

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · implies

Before

y(0)=8; expected=8

After

value condition: Yes

Conditions: none

Check the initial value condition first.

Step identifiers and dependencies

Rule: initial_value_check · Uses: G001, S011

S013 · implies

Before

y′(0)=0; expected=0

After

derivative condition: Yes

Conditions: none

Independently check the derivative condition rather than only one condition.

Step identifiers and dependencies

Rule: initial_derivative_check · Uses: G001, S012

S014 · implies

Before

both conditions=Yes

After

initial conditions do not by themselves certify the ODE

Conditions: none

Even two satisfied initial conditions do not prove that the candidate satisfies a differential equation.

Step identifiers and dependencies

Rule: initial_not_differential_equation · Uses: G001, S013

Reverse checks

  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S012 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S011 · premise_and_result_audit — Recompute y′ Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute y′ Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S008 · premise_and_result_audit — Recompute y Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute y Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute y Horner add degree1 with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute y Horner multiply before degree1 with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S003 · premise_and_result_audit — Recompute y′ coefficient at degree1 with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute y′ coefficient at degree0 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

([8, 0, 2], 0, 8, 0, 8, 0, Yes, Yes, 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: d3bb50d06f966e2c9c9472d2e08e14d8f979fc9b30a9907d9baa5b71def3b687
  • candidate record SHA-256: b8c13cf9c921d42c169d4b2897467a4f5d594e6917c5b3020479ea89473b2e57
  • semantic review receipt SHA-256: 340d74dcc6e37df6249594a0b79a9ee2af804337b7847478b3c1342af9722861
  • question-first witness SHA-256: 9a06233d190d31a16f13fb03b6c3ceba4cbb748fff6c997941f66ab1888dcca8
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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