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Question 23065: Exact Falling Factorials Preserve Low-to-High Derivative Coefficients

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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R0045-23065 · q-20261014-advance-20261111-r02-higher-order-derivative-0040

Original question and givens

Use original low-to-high coefficients=[15, 30, 45, 60, 75, 90] for f(t)=sum coefficients[k]*t^k and derivative order=0≥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. Evaluation point=2. Give (coefficients, order, derivative_coefficients, point, value, certificate).

  • G001 — Use original low-to-high coefficients=[15, 30, 45, 60, 75, 90] for f(t)=sum coefficients[k]*t^k and derivative order=0≥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. Evaluation point=2. Give (coefficients, order, derivative_coefficients, point, value, 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-polynomial-nth-derivative;original snapshot and mathematics retained

After

explicit ordered source output fields=[coefficients, order, derivative_coefficients, point, value, 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=[15, 30, 45, 60, 75, 90];declared order=0

After

declared degree BOUND=5=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 · implies

Before

ORIGINAL coefficients=[15, 30, 45, 60, 75, 90];order=0;declared degree bound=5

After

final derivative coefficients=[15, 30, 45, 60, 75, 90];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, S002

S004 · calculation

Before

Higher derivative Horner power5 previous value times ORIGINAL point := mul(0, 2)

After

Higher derivative Horner power5 previous value times ORIGINAL point = 0

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 Horner power5 plus ORIGINAL derivative coefficient := sum(0, 90)

After

Higher derivative Horner power5 plus ORIGINAL derivative coefficient = 90

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 Horner power4 previous value times ORIGINAL point := mul(90, 2)

After

Higher derivative Horner power4 previous value times ORIGINAL point = 180

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 · calculation

Before

Higher derivative Horner power4 plus ORIGINAL derivative coefficient := sum(180, 75)

After

Higher derivative Horner power4 plus ORIGINAL derivative coefficient = 255

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, S006

S008 · calculation

Before

Higher derivative Horner power3 previous value times ORIGINAL point := mul(255, 2)

After

Higher derivative Horner power3 previous value times ORIGINAL point = 510

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 Horner power3 plus ORIGINAL derivative coefficient := sum(510, 60)

After

Higher derivative Horner power3 plus ORIGINAL derivative coefficient = 570

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 Horner power2 previous value times ORIGINAL point := mul(570, 2)

After

Higher derivative Horner power2 previous value times ORIGINAL point = 1140

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 · calculation

Before

Higher derivative Horner power2 plus ORIGINAL derivative coefficient := sum(1140, 45)

After

Higher derivative Horner power2 plus ORIGINAL derivative coefficient = 1185

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, S010

S012 · calculation

Before

Higher derivative Horner power1 previous value times ORIGINAL point := mul(1185, 2)

After

Higher derivative Horner power1 previous value times ORIGINAL point = 2370

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 Horner power1 plus ORIGINAL derivative coefficient := sum(2370, 30)

After

Higher derivative Horner power1 plus ORIGINAL derivative coefficient = 2400

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 · calculation

Before

Higher derivative Horner power0 previous value times ORIGINAL point := mul(2400, 2)

After

Higher derivative Horner power0 previous value times ORIGINAL point = 4800

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, S013

S015 · calculation

Before

Higher derivative Horner power0 plus ORIGINAL derivative coefficient := sum(4800, 15)

After

Higher derivative Horner power0 plus ORIGINAL derivative coefficient = 4815

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

Reverse checks

  • S015 · premise_and_result_audit — Recompute Higher derivative Horner power0 plus ORIGINAL derivative coefficient with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Recompute Higher derivative Horner power0 previous value times ORIGINAL point with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute Higher derivative Horner power1 plus ORIGINAL derivative coefficient with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute Higher derivative Horner power1 previous value times ORIGINAL point with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute Higher derivative Horner power2 plus ORIGINAL derivative coefficient with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute Higher derivative Horner power2 previous value times ORIGINAL point with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute Higher derivative Horner power3 plus ORIGINAL derivative coefficient with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute Higher derivative Horner power3 previous value times ORIGINAL point with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute Higher derivative Horner power4 plus ORIGINAL derivative coefficient with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Higher derivative Horner power4 previous value times ORIGINAL point with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Higher derivative Horner power5 plus ORIGINAL derivative coefficient with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Higher derivative Horner power5 previous value times ORIGINAL point with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • 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

([15, 30, 45, 60, 75, 90], 0, [15, 30, 45, 60, 75, 90], 2, 4815, falling_factorial_coefficients_exact)

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: dd898a7f129fe4461a3bfee00174e6f1f935440b9388129a8187d94a74bbd0c1
  • candidate record SHA-256: 00491b90097fef98b8fadae94749c46d8cc0aed4ec4dd0d950bed123158eba15
  • semantic review receipt SHA-256: 357d7ad7a6726b2a757558d3b9586a408ade06526cc023da093719c292704438
  • question-first witness SHA-256: 99cefe17e98c7a74321801cf72df6d02fc95b6a6b78aa335accb7e11ed467b2a
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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