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Question 23043: Order Zero Is the Original Function; Later Orders Need the Recursive Chain

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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R0045-23043 · q-20261014-advance-20261111-r02-higher-order-derivative-0018

Original question and givens

Use original low-to-high coefficients=[18, 36, 54, 72, 90] for f(t)=sum coefficients[k]*t^k and derivative order=5≥0. f^(0)=f and each further order differentiates the preceding function. The declared degree bound is coefficient-list length minus1; trailing zeros would make it an upper bound rather than a minimal degree. Give (declared_degree_bound, order, nonnegative_order, order_convention, polynomial_chain_certificate).

  • G001 — Use original low-to-high coefficients=[18, 36, 54, 72, 90] for f(t)=sum coefficients[k]*t^k and derivative order=5≥0. f^(0)=f and each further order differentiates the preceding function. The declared degree bound is coefficient-list length minus1; trailing zeros would make it an upper bound rather than a minimal degree. Give (declared_degree_bound, order, nonnegative_order, order_convention, polynomial_chain_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 operation=higher-order-qualification;original snapshot and mathematics retained

After

explicit ordered source output fields=[declared_degree_bound, order, nonnegative_order, order_convention, polynomial_chain_certificate]

Conditions: none

Retain the historical interface marker while listing source fields without JavaScript.Tags and No retain their claim scope;source-protocol ordering is not a mathematical proof.

Step identifiers and dependencies

Rule: source_ordered_interface_explicit_without_javascript · Uses: G001

S002 · implies

Before

ORIGINAL low-to-high coefficients=[18, 36, 54, 72, 90];declared order=5

After

declared degree BOUND=4=ORIGINAL length-1;initialize derivative order0 with the UNTRIMMED original list

Conditions: none

Length minus1 is the declared bound;do not trim trailing zeros.Order0 is the original function.The monomial rule and finite sums justify each polynomial derivative,not an infinite extrapolation for arbitrary functions.

Step identifiers and dependencies

Rule: higher_ORIGINAL_low_to_high_coefficients_degree_BOUND_order0 · Uses: G001, S001

S003 · calculation

Before

Higher derivative level1 ORIGINAL power1 coefficient product := mul(36, 1)

After

Higher derivative level1 ORIGINAL power1 coefficient product = 36

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

Higher derivative level1 ORIGINAL power2 coefficient product := mul(54, 2)

After

Higher derivative level1 ORIGINAL power2 coefficient product = 108

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

Higher derivative level1 ORIGINAL power3 coefficient product := mul(72, 3)

After

Higher derivative level1 ORIGINAL power3 coefficient product = 216

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Higher derivative level1 ORIGINAL power4 coefficient product := mul(90, 4)

After

Higher derivative level1 ORIGINAL power4 coefficient product = 360

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · implies

Before

previous derivative order=0;actual low-to-high list=[18, 36, 54, 72, 90];drop ONLY its constant term

After

ALL [old_power,old_coefficient,multiplier,new_coefficient] rows=[[1, 36, 1, 36], [2, 54, 2, 108], [3, 72, 3, 216], [4, 90, 4, 360]];next raw list=[36, 108, 216, 360];all intermediate products SAFE

Conditions: none

At each level multiply the original coefficient by its old power k and place it at k−1 in low-to-high order.Once exhausted,the raw list stays empty and is normalized to[0] only at the end.The English source requires every intermediate product SAFE,not merely the final value.

Step identifiers and dependencies

Rule: higher_EVERY_recursive_derivative_level_not_reordered · Uses: G001, S006

S008 · calculation

Before

Higher derivative level2 ORIGINAL power1 coefficient product := mul(108, 1)

After

Higher derivative level2 ORIGINAL power1 coefficient product = 108

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

Higher derivative level2 ORIGINAL power2 coefficient product := mul(216, 2)

After

Higher derivative level2 ORIGINAL power2 coefficient product = 432

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

Higher derivative level2 ORIGINAL power3 coefficient product := mul(360, 3)

After

Higher derivative level2 ORIGINAL power3 coefficient product = 1080

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · implies

Before

previous derivative order=1;actual low-to-high list=[36, 108, 216, 360];drop ONLY its constant term

After

ALL [old_power,old_coefficient,multiplier,new_coefficient] rows=[[1, 108, 1, 108], [2, 216, 2, 432], [3, 360, 3, 1080]];next raw list=[108, 432, 1080];all intermediate products SAFE

Conditions: none

At each level multiply the original coefficient by its old power k and place it at k−1 in low-to-high order.Once exhausted,the raw list stays empty and is normalized to[0] only at the end.The English source requires every intermediate product SAFE,not merely the final value.

Step identifiers and dependencies

Rule: higher_EVERY_recursive_derivative_level_not_reordered · Uses: G001, S010

S012 · calculation

Before

Higher derivative level3 ORIGINAL power1 coefficient product := mul(432, 1)

After

Higher derivative level3 ORIGINAL power1 coefficient product = 432

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

Higher derivative level3 ORIGINAL power2 coefficient product := mul(1080, 2)

After

Higher derivative level3 ORIGINAL power2 coefficient product = 2160

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · implies

Before

previous derivative order=2;actual low-to-high list=[108, 432, 1080];drop ONLY its constant term

After

ALL [old_power,old_coefficient,multiplier,new_coefficient] rows=[[1, 432, 1, 432], [2, 1080, 2, 2160]];next raw list=[432, 2160];all intermediate products SAFE

Conditions: none

At each level multiply the original coefficient by its old power k and place it at k−1 in low-to-high order.Once exhausted,the raw list stays empty and is normalized to[0] only at the end.The English source requires every intermediate product SAFE,not merely the final value.

Step identifiers and dependencies

Rule: higher_EVERY_recursive_derivative_level_not_reordered · Uses: G001, S013

S015 · calculation

Before

Higher derivative level4 ORIGINAL power1 coefficient product := mul(2160, 1)

After

Higher derivative level4 ORIGINAL power1 coefficient product = 2160

Conditions: none

Substitute this question's original roles,order and established intermediates exactly,not floats or another question's data.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · implies

Before

previous derivative order=3;actual low-to-high list=[432, 2160];drop ONLY its constant term

After

ALL [old_power,old_coefficient,multiplier,new_coefficient] rows=[[1, 2160, 1, 2160]];next raw list=[2160];all intermediate products SAFE

Conditions: none

At each level multiply the original coefficient by its old power k and place it at k−1 in low-to-high order.Once exhausted,the raw list stays empty and is normalized to[0] only at the end.The English source requires every intermediate product SAFE,not merely the final value.

Step identifiers and dependencies

Rule: higher_EVERY_recursive_derivative_level_not_reordered · Uses: G001, S015

S017 · implies

Before

previous derivative order=4;actual low-to-high list=[2160];drop ONLY its constant term

After

ALL [old_power,old_coefficient,multiplier,new_coefficient] rows=[];next raw list=[];all intermediate products SAFE

Conditions: none

At each level multiply the original coefficient by its old power k and place it at k−1 in low-to-high order.Once exhausted,the raw list stays empty and is normalized to[0] only at the end.The English source requires every intermediate product SAFE,not merely the final value.

Step identifiers and dependencies

Rule: higher_EVERY_recursive_derivative_level_not_reordered · Uses: G001, S016

S018 · implies

Before

ORIGINAL coefficients=[18, 36, 54, 72, 90];order=5;declared degree bound=4

After

final derivative coefficients=[0];for each original power k>=order multiplier=k*(k-1)*...*(k-order+1);lower powers vanish

Conditions: none

Repeated differentiation gives the falling factorial in original coefficient order;orders above the declared bound vanish.This gives no analyticity claim for arbitrary differentiable functions and does not turn a trailing-zero bound into the minimal degree.

Step identifiers and dependencies

Rule: higher_falling_factorial_rule_all_orders_polynomial_only · Uses: G001, S017

Reverse checks

  • 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 — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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 — Recompute Higher derivative level4 ORIGINAL power1 coefficient product with exact rational arithmetic, not rounded decimals.
  • 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 Higher derivative level3 ORIGINAL power2 coefficient product with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute Higher derivative level3 ORIGINAL power1 coefficient product 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 Higher derivative level2 ORIGINAL power3 coefficient product with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute Higher derivative level2 ORIGINAL power2 coefficient product with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute Higher derivative level2 ORIGINAL power1 coefficient product with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S006 · premise_and_result_audit — Recompute Higher derivative level1 ORIGINAL power4 coefficient product with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Higher derivative level1 ORIGINAL power3 coefficient product with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Higher derivative level1 ORIGINAL power2 coefficient product with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute Higher derivative level1 ORIGINAL power1 coefficient product 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

(4, 5, Yes, recursive_derivative_chain_required, 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: 60b3e05aa7bf07a8efeb2f8bda5efe12376d1fc775725a7228cc5124b8f76b22
  • candidate record SHA-256: 1a14fb0ac2c228764e683544178566262c996f22ca75334fc703faac861a0a1e
  • semantic review receipt SHA-256: 357d7ad7a6726b2a757558d3b9586a408ade06526cc023da093719c292704438
  • question-first witness SHA-256: 99cefe17e98c7a74321801cf72df6d02fc95b6a6b78aa335accb7e11ed467b2a
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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