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Question 2278: Value and Slope Initial Data as Separate 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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R0003-02278 · q-20261013-advance-20261021-r04-initial-value-problem-0028

Original question and givens

Use the integer polynomial candidate with ascending-power coefficients=[-8, -1, 2]. Initial data and ODE residuals are separate obligations. Neither a finite grid nor an initial-value match proves existence, uniqueness, a general solution or an identity on an entire interval. x0=0, required y0=-8, required y_prime0=-1. Give (coefficients,x0,y(x0),y'(x0),required y0,required y_prime0,value match?,derivative match?,both?).

  • G001 — Use the integer polynomial candidate with ascending-power coefficients=[-8, -1, 2]. Initial data and ODE residuals are separate obligations. Neither a finite grid nor an initial-value match proves existence, uniqueness, a general solution or an identity on an entire interval. x0=0, required y0=-8, required y_prime0=-1. Give (coefficients,x0,y(x0),y'(x0),required y0,required y_prime0,value match?,derivative match?,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 polynomial ascending coefficients=[-8, -1, 2]

After

initial point=0; required y₀=-8

Conditions: none

Retain the polynomial and initial data;the residual grid need not contain the initial point,so evaluate it separately.

Step identifiers and dependencies

Rule: candidate_IVP_data · Uses: G001

S002 · calculation

Before

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

After

y′ coefficient at degree0 = -1

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

initial y ascending coefficients=[-8, -1, 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

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

After

initial 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

initial y Horner add degree1 := sum(0, -1)

After

initial y Horner add degree1 = -1

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

initial y Horner multiply before degree0 := mul(-1, 0)

After

initial 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

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

After

initial 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

initial y′ ascending coefficients=[-1, 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

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

After

initial 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

initial y′ Horner add degree0 := sum(0, -1)

After

initial y′ Horner add degree0 = -1

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; required=-8

After

value condition=Yes

Conditions: none

Compare the actual function value at the initial point,not another grid point.

Step identifiers and dependencies

Rule: initial_value_condition · Uses: G001, S011

S013 · implies

Before

y′(0)=-1; required=-1

After

derivative condition=Yes

Conditions: none

Second-order initial data also require the derivative condition;the two conditions cannot replace one another.

Step identifiers and dependencies

Rule: initial_derivative_condition · Uses: G001, S012

S014 · implies

Before

initial data agree or disagree

After

no differential-equation assertion from initial data alone

Conditions: none

Matching initial data do not by themselves check the differential equation or prove an existence-uniqueness theorem.

Step identifiers and dependencies

Rule: initial_only_scope · 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 initial y′ Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute initial 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 initial y Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute initial y Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute initial y Horner add degree1 with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute initial 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, -1, 2], 0, -8, -1, -8, -1, 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: bc9825662274544ec48d59b96b20ea0334c2eff88f1e089a0b9cfb10b97c6bed
  • candidate record SHA-256: b2870f2235a3820437e7e3a4ad2141c4d68945dc3610f06adf83513bf9bb1b2f
  • semantic review receipt SHA-256: 5dbc70ebd5f74b23384c93b63a2b1d6519e206c79f22ae16a6c2d7483cea783f
  • question-first witness SHA-256: cf121c8dd2fec13aa118b04b049ee39494f1d6d9ecdc13514cafb78c0fc021fa
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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