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Question 3854: Exact Moment Integral Minus a Finite Left Sum

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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← Question derivation index · Original question batch

R0006-03854 · q-20261007-advance-20261009-r06-definite-integral-0054

Original question and givens

On all R, f(x)=(-4)x+(-9). On a=1≤b=5, use N=4 uniform left cells. Find the signed error I−S_N, exact moment integral minus the finite left sum. Use reduced positive-denominator fractions, retaining /1 for integers.

  • G001 — On all R, f(x)=(-4)x+(-9). On a=1≤b=5, use N=4 uniform left cells. Find the signed error I−S_N, exact moment integral minus the finite left sum. Use reduced positive-denominator fractions, retaining /1 for integers.

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

explicit real polynomial moment or constant integrand model

After

oriented I(a,b)=H(b)−H(a);do not sort endpoints

Conditions: none

Real polynomials are continuous and integrable;use termwise primitive endpoint differences for exact oriented integrals,not absolute area or a finite sum.

Step identifiers and dependencies

Rule: polynomial_moment_scope · Uses: G001

S002 · calculation

Before

interval width := sub(5, 1)

After

interval width = 4

Conditions: none

Compute the nonnegative interval width,allowing zero width.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

partition step := div(4, 4)

After

partition step = 1

Conditions: none

Divide by positive integer N to get the exact step.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

left sample0 offset := mul(0, 1)

After

left sample0 offset = 0

Conditions: none

Left samples use i=0,...,N−1,not the final right endpoint.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

left sample0 x := sum(1, 0)

After

left sample0 x = 1

Conditions: none

Add the indexed offset to the start.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

left sample0 mx := mul(-4, 1)

After

left sample0 mx = -4

Conditions: none

Evaluate the product term of the affine integrand.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

left sample0 value := sum(-4, -9)

After

left sample0 value = -13

Conditions: none

Add c to obtain this sample value.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

left sample0 rectangle := mul(-13, 1)

After

left sample0 rectangle = -13

Conditions: none

Multiply by the step to get the signed rectangle contribution,without absolute values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · implies

Before

[1, -13, -13]

After

finite left-sum term index=0

Conditions: none

List exactly one left term per subinterval;these are finite-sum data,not a claimed limit proof.

Step identifiers and dependencies

Rule: left_partition_term · Uses: G001, S008

S010 · calculation

Before

left sample1 offset := mul(1, 1)

After

left sample1 offset = 1

Conditions: none

Left samples use i=0,...,N−1,not the final right endpoint.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

left sample1 x := sum(1, 1)

After

left sample1 x = 2

Conditions: none

Add the indexed offset to the start.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · calculation

Before

left sample1 mx := mul(-4, 2)

After

left sample1 mx = -8

Conditions: none

Evaluate the product term of the affine integrand.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

left sample1 value := sum(-8, -9)

After

left sample1 value = -17

Conditions: none

Add c to obtain this sample value.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · calculation

Before

left sample1 rectangle := mul(-17, 1)

After

left sample1 rectangle = -17

Conditions: none

Multiply by the step to get the signed rectangle contribution,without absolute values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · implies

Before

[2, -17, -17]

After

finite left-sum term index=1

Conditions: none

List exactly one left term per subinterval;these are finite-sum data,not a claimed limit proof.

Step identifiers and dependencies

Rule: left_partition_term · Uses: G001, S014

S016 · calculation

Before

left sample2 offset := mul(2, 1)

After

left sample2 offset = 2

Conditions: none

Left samples use i=0,...,N−1,not the final right endpoint.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S015

S017 · calculation

Before

left sample2 x := sum(1, 2)

After

left sample2 x = 3

Conditions: none

Add the indexed offset to the start.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S016

S018 · calculation

Before

left sample2 mx := mul(-4, 3)

After

left sample2 mx = -12

Conditions: none

Evaluate the product term of the affine integrand.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S017

S019 · calculation

Before

left sample2 value := sum(-12, -9)

After

left sample2 value = -21

Conditions: none

Add c to obtain this sample value.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S018

S020 · calculation

Before

left sample2 rectangle := mul(-21, 1)

After

left sample2 rectangle = -21

Conditions: none

Multiply by the step to get the signed rectangle contribution,without absolute values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S019

S021 · implies

Before

[3, -21, -21]

After

finite left-sum term index=2

Conditions: none

List exactly one left term per subinterval;these are finite-sum data,not a claimed limit proof.

Step identifiers and dependencies

Rule: left_partition_term · Uses: G001, S020

S022 · calculation

Before

left sample3 offset := mul(3, 1)

After

left sample3 offset = 3

Conditions: none

Left samples use i=0,...,N−1,not the final right endpoint.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S021

S023 · calculation

Before

left sample3 x := sum(1, 3)

After

left sample3 x = 4

Conditions: none

Add the indexed offset to the start.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S022

S024 · calculation

Before

left sample3 mx := mul(-4, 4)

After

left sample3 mx = -16

Conditions: none

Evaluate the product term of the affine integrand.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S023

S025 · calculation

Before

left sample3 value := sum(-16, -9)

After

left sample3 value = -25

Conditions: none

Add c to obtain this sample value.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S024

S026 · calculation

Before

left sample3 rectangle := mul(-25, 1)

After

left sample3 rectangle = -25

Conditions: none

Multiply by the step to get the signed rectangle contribution,without absolute values.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S025

S027 · implies

Before

[4, -25, -25]

After

finite left-sum term index=3

Conditions: none

List exactly one left term per subinterval;these are finite-sum data,not a claimed limit proof.

Step identifiers and dependencies

Rule: left_partition_term · Uses: G001, S026

S028 · calculation

Before

finite left sum := sum(-13, -17, -21, -25)

After

finite left sum = -76

Conditions: none

Add all N contributions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S027

S029 · calculation

Before

affine integral primitive coefficient1 := div(-9, 1)

After

affine integral primitive coefficient1 = -9

Conditions: none

The primitive coefficient for c·x^k is c/(k+1),with positive nonzero k+1.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S028

S030 · calculation

Before

affine integral primitive coefficient2 := div(-4, 2)

After

affine integral primitive coefficient2 = -2

Conditions: none

The primitive coefficient for c·x^k is c/(k+1),with positive nonzero k+1.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S029

S031 · implies

Before

[0, -9, -2]

After

H′=the supplied polynomial;integrate from 1 to 5

Conditions: none

Termwise differentiation recovers the original coefficients;the integration constant cancels in the endpoint difference.

Step identifiers and dependencies

Rule: polynomial_primitive_identity · Uses: G001, S030

S032 · implies

Before

affine integral H(b) ascending coefficients=[0, -9, -2]

After

evaluate at x=5

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, S031

S033 · calculation

Before

affine integral H(b) Horner multiply before degree1 := mul(-2, 5)

After

affine integral H(b) Horner multiply before degree1 = -10

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S032

S034 · calculation

Before

affine integral H(b) Horner add degree1 := sum(-10, -9)

After

affine integral H(b) Horner add degree1 = -19

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S033

S035 · calculation

Before

affine integral H(b) Horner multiply before degree0 := mul(-19, 5)

After

affine integral H(b) Horner multiply before degree0 = -95

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S034

S036 · calculation

Before

affine integral H(b) Horner add degree0 := sum(-95, 0)

After

affine integral H(b) Horner add degree0 = -95

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S035

S037 · implies

Before

affine integral H(a) ascending coefficients=[0, -9, -2]

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 · calculation

Before

affine integral H(a) Horner multiply before degree1 := mul(-2, 1)

After

affine integral H(a) Horner multiply before degree1 = -2

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S037

S039 · calculation

Before

affine integral H(a) Horner add degree1 := sum(-2, -9)

After

affine integral H(a) Horner add degree1 = -11

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S038

S040 · calculation

Before

affine integral H(a) Horner multiply before degree0 := mul(-11, 1)

After

affine integral H(a) Horner multiply before degree0 = -11

Conditions: none

Multiply by the same evaluation point first.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S039

S041 · calculation

Before

affine integral H(a) Horner add degree0 := sum(-11, 0)

After

affine integral H(a) Horner add degree0 = -11

Conditions: none

Then add the full coefficient at this position.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S040

S042 · calculation

Before

affine integral oriented moment := sub(-95, -11)

After

affine integral oriented moment = -84

Conditions: none

Subtract the starting primitive value from the ending value;reversing endpoints naturally reverses the sign.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S041

S043 · calculation

Before

integral minus left sum := sub(-84, -76)

After

integral minus left sum = -8

Conditions: none

The requested direction is I−S_N;a negative slope may give a negative difference,not absolute error.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S042

S044 · implies

Before

I=-84;S_N=-76;N=4

After

signed finite-sum difference=-8

Conditions: none

This is the exact difference for finite N,not evidence of a general convergence rate or integrability of arbitrary functions.

Step identifiers and dependencies

Rule: finite_sum_vs_integral · Uses: G001, S043

Reverse checks

  • 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 integral minus left sum with exact rational arithmetic, not rounded decimals.
  • S042 · premise_and_result_audit — Recompute affine integral oriented moment with exact rational arithmetic, not rounded decimals.
  • S041 · premise_and_result_audit — Recompute affine integral H(a) Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S040 · premise_and_result_audit — Recompute affine integral H(a) Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S039 · premise_and_result_audit — Recompute affine integral H(a) Horner add degree1 with exact rational arithmetic, not rounded decimals.
  • S038 · premise_and_result_audit — Recompute affine integral H(a) Horner multiply before degree1 with exact rational arithmetic, not rounded decimals.
  • 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 affine integral H(b) Horner add degree0 with exact rational arithmetic, not rounded decimals.
  • S035 · premise_and_result_audit — Recompute affine integral H(b) Horner multiply before degree0 with exact rational arithmetic, not rounded decimals.
  • S034 · premise_and_result_audit — Recompute affine integral H(b) Horner add degree1 with exact rational arithmetic, not rounded decimals.
  • S033 · premise_and_result_audit — Recompute affine integral H(b) Horner multiply before degree1 with exact rational arithmetic, not rounded decimals.
  • S032 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S031 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S030 · premise_and_result_audit — Recompute affine integral primitive coefficient2 with exact rational arithmetic, not rounded decimals.
  • S029 · premise_and_result_audit — Recompute affine integral primitive coefficient1 with exact rational arithmetic, not rounded decimals.
  • S028 · premise_and_result_audit — Recompute finite left sum 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 — Recompute left sample3 rectangle with exact rational arithmetic, not rounded decimals.
  • S025 · premise_and_result_audit — Recompute left sample3 value with exact rational arithmetic, not rounded decimals.
  • S024 · premise_and_result_audit — Recompute left sample3 mx with exact rational arithmetic, not rounded decimals.
  • S023 · premise_and_result_audit — Recompute left sample3 x with exact rational arithmetic, not rounded decimals.
  • S022 · premise_and_result_audit — Recompute left sample3 offset with exact rational arithmetic, not rounded decimals.
  • S021 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.
  • S020 · premise_and_result_audit — Recompute left sample2 rectangle with exact rational arithmetic, not rounded decimals.
  • S019 · premise_and_result_audit — Recompute left sample2 value with exact rational arithmetic, not rounded decimals.
  • S018 · premise_and_result_audit — Recompute left sample2 mx with exact rational arithmetic, not rounded decimals.
  • S017 · premise_and_result_audit — Recompute left sample2 x with exact rational arithmetic, not rounded decimals.
  • S016 · premise_and_result_audit — Recompute left sample2 offset with exact rational arithmetic, not rounded decimals.
  • 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 left sample1 rectangle with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute left sample1 value with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute left sample1 mx with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute left sample1 x with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute left sample1 offset 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 left sample0 rectangle with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute left sample0 value with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute left sample0 mx with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute left sample0 x with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute left sample0 offset with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute partition step with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute interval width 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

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: 826644ea16f2d0479fcdf4bda9007e652504f2f8ec27e2ddedd09b60d767f337
  • candidate record SHA-256: 6032d3b9aa43f5e297c856f29465195491ebcaa1611d2694b36fb33555f5b564
  • semantic review receipt SHA-256: 568eefd71709ac3dc16a0d5b3b4ad3e83376a8ef300c9e5493eee0721500b29d
  • question-first witness SHA-256: d964b91bedb9d4918bbc055f567762a09f5a58af6c876268e719d5100332d855
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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