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Question 23641: The One-Sided Tail Is a Limit of Finite-Cutoff Integrals

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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R0046-23641 · q-20261014-advance-20261112-r04-improper-integral-0016

Original question and givens

Use f(x)=16/x^5 on [1,infinity), with integer exponent≥2 and lower≥1. Give (integrand, interval, integral, converges, certificate).

  • G001 — Use f(x)=16/x^5 on [1,infinity), with integer exponent≥2 and lower≥1. Give (integrand, interval, integral, converges, 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=improper-one-sided-tail;original snapshot and mathematics retained

After

explicit ordered source output fields=[integrand, interval, integral, converges, certificate]

Conditions: none

Keep the source snapshot while listing ordered fields without JavaScript.Radius uses its original mode to select6 or11 fields without padding;distinguish nonclaims from actual negations.

Step identifiers and dependencies

Rule: source_ordered_interface_explicit_without_javascript · Uses: G001

S002 · calculation

Before

Improper ORIGINAL positive tail lower positive power step1 := mul(1, 1)

After

Improper ORIGINAL positive tail lower positive power step1 = 1

Conditions: none

Substitute original roles and established intermediates exactly,without floats or treating finite tests as universal limits.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

Improper ORIGINAL positive tail lower positive power step2 := mul(1, 1)

After

Improper ORIGINAL positive tail lower positive power step2 = 1

Conditions: none

Substitute original roles and established intermediates exactly,without floats or treating finite tests as universal limits.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · calculation

Before

Improper ORIGINAL positive tail lower positive power step3 := mul(1, 1)

After

Improper ORIGINAL positive tail lower positive power step3 = 1

Conditions: none

Substitute original roles and established intermediates exactly,without floats or treating finite tests as universal limits.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S003

S005 · calculation

Before

Improper ORIGINAL positive tail lower positive power step4 := mul(1, 1)

After

Improper ORIGINAL positive tail lower positive power step4 = 1

Conditions: none

Substitute original roles and established intermediates exactly,without floats or treating finite tests as universal limits.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Improper ORIGINAL positive tail exponent-minus-one times lower-power := mul(4, 1)

After

Improper ORIGINAL positive tail exponent-minus-one times lower-power = 4

Conditions: none

Substitute original roles and established intermediates exactly,without floats or treating finite tests as universal limits.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

Improper ORIGINAL positive tail exact antiderivative limit value := div(16, 4)

After

Improper ORIGINAL positive tail exact antiderivative limit value = 4

Conditions: none

Substitute original roles and established intermediates exactly,without floats or treating finite tests as universal limits.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · implies

Before

Improper ORIGINAL positive tail:ORIGINAL scale=16,exponent=5>1,lower=1>=1;integrand scale/x^exponent

After

for EVERY B>=lower,integral_lower^B=scale/(exponent-1)*(lower^(1-exponent)-B^(1-exponent));B^(1-exponent) tends0,so limit=4

Conditions: none

Because k>1,the negative power tends0.The absolute tail error is |scale|/((k−1)B^(k−1)),which is below any epsilon for sufficiently large B.Signed or zero scale is allowed;this is a universal limit,not sampled cutoffs.

Step identifiers and dependencies

Rule: improper_WHOLE_one_sided_tail_antiderivative_limit_not_samples · Uses: G001, S007

Reverse checks

  • 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 Improper ORIGINAL positive tail exact antiderivative limit value with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Improper ORIGINAL positive tail exponent-minus-one times lower-power with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Improper ORIGINAL positive tail lower positive power step4 with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Recompute Improper ORIGINAL positive tail lower positive power step3 with exact rational arithmetic, not rounded decimals.
  • S003 · premise_and_result_audit — Recompute Improper ORIGINAL positive tail lower positive power step2 with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute Improper ORIGINAL positive tail lower positive power step1 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

(f(x)=16/x^5, [1,infinity), 4, Yes, limit_of_integrals_from_lower_to_b_as_b_tends_to_infinity)

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: 6c03b92d078bf26be36521627f36415416cac88e2f98c62c695cf38e0376306f
  • candidate record SHA-256: 27e84ab3d7bdb6124601cbbb4f8ce4e2404b7e24860878a76ba6674293a51333
  • semantic review receipt SHA-256: a7c0d888ade6d307703c4222c4137c78c0d2448babdcba2fa3446fe6fdd343c1
  • question-first witness SHA-256: c9571f97a37d503ad6a61034cc00108543a05c37ef246d1c4962f55136a3de02
  • Lean: NOT_RUN · human review: NOT_PERFORMED
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