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Question 2253: A Second-Order Candidate with Two Initial Data

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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R0003-02253 · q-20261013-advance-20261021-r04-initial-value-problem-0078

Original question and givens

Use the integer polynomial candidate with ascending-power coefficients=[-10, -1, 0]. 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. Relation a*y''+b*y'+c*y=rhs has a=1≠0, b=0, c=0, rhs=0; input grid=[-1, 0, 1], x0=0, required y0=-10, required y_prime0=-1. Use sorted distinct grid points. Give (coefficients,a,b,c,rhs,grid,every [x,y,y',y'',signed residual,zero?] row,x0,y(x0),y'(x0),required y0,required y_prime0,value match?,derivative match?,all grid and both initial checks?).

  • G001 — Use the integer polynomial candidate with ascending-power coefficients=[-10, -1, 0]. 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. Relation a*y''+b*y'+c*y=rhs has a=1≠0, b=0, c=0, rhs=0; input grid=[-1, 0, 1], x0=0, required y0=-10, required y_prime0=-1. Use sorted distinct grid points. Give (coefficients,a,b,c,rhs,grid,every [x,y,y',y'',signed residual,zero?] row,x0,y(x0),y'(x0),required y0,required y_prime0,value match?,derivative match?,all grid and both initial checks?).

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=[-10, -1, 0]

After

initial point=0; required y₀=-10

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, 0)

After

y′ coefficient at degree1 = 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, S002

S004 · 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, S003

S005 · implies

Before

initial y ascending coefficients=[-10, -1, 0]

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, S004

S006 · 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, S005

S007 · calculation

Before

initial y Horner add degree0 := sum(0, -10)

After

initial y Horner add degree0 = -10

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · implies

Before

initial y′ ascending coefficients=[-1, 0]

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, S007

S009 · implies

Before

y(0)=-10; required=-10

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, S008

S010 · 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, S009

S011 · implies

Before

[-1, 0, 1]

After

distinct ordered audit grid=[-1, 0, 1]

Conditions: none

Deduplication and sorting fix presentation;every listed distinct point is then audited.

Step identifiers and dependencies

Rule: finite_grid_domain · Uses: G001, S010

S012 · implies

Before

y at-1 ascending coefficients=[-10, -1, 0]

After

evaluate at x=-1

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, S011

S013 · calculation

Before

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

After

y at-1 Horner multiply before degree0 = 1

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · calculation

Before

y at-1 Horner add degree0 := sum(1, -10)

After

y at-1 Horner add degree0 = -9

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · implies

Before

y′ at-1 ascending coefficients=[-1, 0]

After

evaluate at x=-1

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, S014

S016 · implies

Before

y″ at-1 ascending coefficients=[0]

After

evaluate at x=-1

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, S015

S017 · calculation

Before

a·y″ at-1 := mul(1, 0)

After

a·y″ at-1 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · calculation

Before

b·y′ at-1 := mul(0, -1)

After

b·y′ at-1 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S017

S019 · calculation

Before

c·y at-1 := mul(0, -9)

After

c·y at-1 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · calculation

Before

left side at-1 := sum(0, 0, 0)

After

left side at-1 = 0

Conditions: none

First sum the complete left side.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S019

S021 · calculation

Before

residual at-1 := sub(0, 0)

After

residual at-1 = 0

Conditions: none

Define the residual as left side minus right side.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S020

S022 · implies

Before

residual at-1=0

After

point equation match=Yes

Conditions: none

This flag answers only for the current grid point.

Step identifiers and dependencies

Rule: point_equation_check · Uses: G001, S021

S023 · implies

Before

y at0 ascending coefficients=[-10, -1, 0]

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, S022

S024 · calculation

Before

y at0 Horner multiply before degree0 := mul(-1, 0)

After

y at0 Horner multiply before degree0 = 0

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S023

S025 · calculation

Before

y at0 Horner add degree0 := sum(0, -10)

After

y at0 Horner add degree0 = -10

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S024

S026 · implies

Before

y′ at0 ascending coefficients=[-1, 0]

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, S025

S027 · implies

Before

y″ at0 ascending coefficients=[0]

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, S026

S028 · calculation

Before

a·y″ at0 := mul(1, 0)

After

a·y″ at0 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S027

S029 · calculation

Before

b·y′ at0 := mul(0, -1)

After

b·y′ at0 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S028

S030 · calculation

Before

c·y at0 := mul(0, -10)

After

c·y at0 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S029

S031 · calculation

Before

left side at0 := sum(0, 0, 0)

After

left side at0 = 0

Conditions: none

First sum the complete left side.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S030

S032 · calculation

Before

residual at0 := sub(0, 0)

After

residual at0 = 0

Conditions: none

Define the residual as left side minus right side.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S031

S033 · implies

Before

residual at0=0

After

point equation match=Yes

Conditions: none

This flag answers only for the current grid point.

Step identifiers and dependencies

Rule: point_equation_check · Uses: G001, S032

S034 · implies

Before

y at1 ascending coefficients=[-10, -1, 0]

After

evaluate at x=1

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, S033

S035 · calculation

Before

y at1 Horner multiply before degree0 := mul(-1, 1)

After

y at1 Horner multiply before degree0 = -1

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S034

S036 · calculation

Before

y at1 Horner add degree0 := sum(-1, -10)

After

y at1 Horner add degree0 = -11

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S035

S037 · implies

Before

y′ at1 ascending coefficients=[-1, 0]

After

evaluate at x=1

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, S036

S038 · implies

Before

y″ at1 ascending coefficients=[0]

After

evaluate at x=1

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, S037

S039 · calculation

Before

a·y″ at1 := mul(1, 0)

After

a·y″ at1 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S038

S040 · calculation

Before

b·y′ at1 := mul(0, -1)

After

b·y′ at1 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S039

S041 · calculation

Before

c·y at1 := mul(0, -11)

After

c·y at1 = 0

Conditions: none

Multiply each derivative by its own equation coefficient.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S040

S042 · calculation

Before

left side at1 := sum(0, 0, 0)

After

left side at1 = 0

Conditions: none

First sum the complete left side.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S041

S043 · calculation

Before

residual at1 := sub(0, 0)

After

residual at1 = 0

Conditions: none

Define the residual as left side minus right side.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S042

S044 · implies

Before

residual at1=0

After

point equation match=Yes

Conditions: none

This flag answers only for the current grid point.

Step identifiers and dependencies

Rule: point_equation_check · Uses: G001, S043

S045 · implies

Before

all listed grid points pass=Yes; initial conditions pass=Yes

After

combined finite check=Yes

Conditions: none

Every requested grid and initial condition must pass;do not omit a point or an initial condition.

Step identifiers and dependencies

Rule: finite_grid_initial_conjunction · Uses: G001, S044

S046 · implies

Before

finite grid agreement alone is not a general interval certificate

After

a polynomial coefficient/degree certificate is a separate possible strengthening

Conditions: none

For these polynomials,coefficient identity or a proved degree bound with enough distinct points could separately strengthen the evidence;this output flag records only the finite check,not a denial of that additional method.

Step identifiers and dependencies

Rule: grid_vs_interval_scope · Uses: G001, S045

Reverse checks

  • S046 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S045 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S044 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S043 · premise_and_result_audit — Recompute residual at1 with exact rational arithmetic, not rounded decimals.
  • S042 · premise_and_result_audit — Recompute left side at1 with exact rational arithmetic, not rounded decimals.
  • S041 · premise_and_result_audit — Recompute c·y at1 with exact rational arithmetic, not rounded decimals.
  • S040 · premise_and_result_audit — Recompute b·y′ at1 with exact rational arithmetic, not rounded decimals.
  • S039 · premise_and_result_audit — Recompute a·y″ at1 with exact rational arithmetic, not rounded decimals.
  • S038 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S037 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S036 · premise_and_result_audit — Recompute y at1 Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S035 · premise_and_result_audit — Recompute y at1 Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S034 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S033 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S032 · premise_and_result_audit — Recompute residual at0 with exact rational arithmetic, not rounded decimals.
  • S031 · premise_and_result_audit — Recompute left side at0 with exact rational arithmetic, not rounded decimals.
  • S030 · premise_and_result_audit — Recompute c·y at0 with exact rational arithmetic, not rounded decimals.
  • S029 · premise_and_result_audit — Recompute b·y′ at0 with exact rational arithmetic, not rounded decimals.
  • S028 · premise_and_result_audit — Recompute a·y″ at0 with exact rational arithmetic, not rounded decimals.
  • S027 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S026 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S025 · premise_and_result_audit — Recompute y at0 Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S024 · premise_and_result_audit — Recompute y at0 Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S023 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S022 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S021 · premise_and_result_audit — Recompute residual at-1 with exact rational arithmetic, not rounded decimals.
  • S020 · premise_and_result_audit — Recompute left side at-1 with exact rational arithmetic, not rounded decimals.
  • S019 · premise_and_result_audit — Recompute c·y at-1 with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Recompute b·y′ at-1 with exact rational arithmetic, not rounded decimals.
  • S017 · premise_and_result_audit — Recompute a·y″ at-1 with exact rational arithmetic, not rounded decimals.
  • S016 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 — Recompute y at-1 Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute y at-1 Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S010 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S007 · premise_and_result_audit — Recompute initial y Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute initial y Horner multiply before degree0 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 y″ coefficient at degree0 with exact rational arithmetic, not rounded decimals.
  • 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

([-10, -1, 0], 1, 0, 0, 0, [-1, 0, 1], [[-1, -9, -1, 0, 0, Yes], [0, -10, -1, 0, 0, Yes], [1, -11, -1, 0, 0, Yes]], 0, -10, -1, -10, -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: 508eed1213d43f1c678f205e44fb5c1f8303f933c357b7dbf77946b32cdaf02b
  • candidate record SHA-256: 5054a26b35a33ecceb01eccb8a785dd0243412b30dbeb90cb1da0e637cdd22f9
  • semantic review receipt SHA-256: 5dbc70ebd5f74b23384c93b63a2b1d6519e206c79f22ae16a6c2d7483cea783f
  • question-first witness SHA-256: cf121c8dd2fec13aa118b04b049ee39494f1d6d9ecdc13514cafb78c0fc021fa
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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