Explore related knowledge and questions →

Question 28091: An Exact Root Stops before Any Newton Division

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

Return to catalogue page 141

← Question derivation index · Original question batch

R0055-28091 · q-20261015-pulse-20261119-r01-0016

Original question and givens

Coefficients in low-to-high degree order are=[-16, 0, 1]; all iterations use exact rational arithmetic. The current iterate is x=2. Give (coefficients_low_to_high, current_iterate, function_value, derivative_value, status, next_iterate_or_null, root_first_convention).

  • G001 — Coefficients in low-to-high degree order are=[-16, 0, 1]; all iterations use exact rational arithmetic. The current iterate is x=2. Give (coefficients_low_to_high, current_iterate, function_value, derivative_value, status, next_iterate_or_null, root_first_convention).

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 roles = [qf-mod50-newton-step, newton-step]

After

derived = [[coefficients_low_to_high, current_iterate, function_value, derivative_value, status, next_iterate_or_null, root_first_convention]]

Conditions: none

List this scalar/label/set/point answer role or mode-specific ordered fields,not an imposed universal tuple.Retain legacy domain/underscore operation and integer fractions with/1;original bilingual snapshots stay unchanged.

Step identifiers and dependencies

Rule: source_answer_roles_or_ordered_fields_without_JS · Uses: G001

S002 · calculation

Before

Newton ORIGINAL polynomial ORIGINAL derivative coefficient1 := mul(1, 0)

After

Newton ORIGINAL polynomial ORIGINAL derivative coefficient1 = 0

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S001

S003 · calculation

Before

Newton ORIGINAL polynomial ORIGINAL derivative coefficient2 := mul(2, 1)

After

Newton ORIGINAL polynomial ORIGINAL derivative coefficient2 = 2

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S002

S004 · implies

Before

source roles = [Newton ORIGINAL polynomial, [-16, 0, 1]]

After

derived = [[-16, 0, 1], [0, 2]]

Conditions: none

Require raw length2..6 before trimming trailing zeros,and remain nonconstant.Differentiate every monomial to i*c_i*x^(i-1).Source derivative coefficients must pass their1e8 profile even if a root later stops or steps=0.

Step identifiers and dependencies

Rule: Newton_polynomial_raw_arity_trim_nonconstant_AND_ALL_derivative_coefficients · Uses: G001, S003

S005 · calculation

Before

Newton ORIGINAL step f ORIGINAL Horner multiply degree2 := mul(0, 2)

After

Newton ORIGINAL step f ORIGINAL Horner multiply degree2 = 0

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S004

S006 · calculation

Before

Newton ORIGINAL step f ORIGINAL Horner add coefficient2 := sum(0, 1)

After

Newton ORIGINAL step f ORIGINAL Horner add coefficient2 = 1

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S005

S007 · calculation

Before

Newton ORIGINAL step f ORIGINAL Horner multiply degree1 := mul(1, 2)

After

Newton ORIGINAL step f ORIGINAL Horner multiply degree1 = 2

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S006

S008 · calculation

Before

Newton ORIGINAL step f ORIGINAL Horner add coefficient1 := sum(2, 0)

After

Newton ORIGINAL step f ORIGINAL Horner add coefficient1 = 2

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S007

S009 · calculation

Before

Newton ORIGINAL step f ORIGINAL Horner multiply degree0 := mul(2, 2)

After

Newton ORIGINAL step f ORIGINAL Horner multiply degree0 = 4

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S008

S010 · calculation

Before

Newton ORIGINAL step f ORIGINAL Horner add coefficient0 := sum(4, -16)

After

Newton ORIGINAL step f ORIGINAL Horner add coefficient0 = -12

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S009

S011 · calculation

Before

Newton ORIGINAL step fprime ORIGINAL Horner multiply degree1 := mul(0, 2)

After

Newton ORIGINAL step fprime ORIGINAL Horner multiply degree1 = 0

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S010

S012 · calculation

Before

Newton ORIGINAL step fprime ORIGINAL Horner add coefficient1 := sum(0, 2)

After

Newton ORIGINAL step fprime ORIGINAL Horner add coefficient1 = 2

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S011

S013 · calculation

Before

Newton ORIGINAL step fprime ORIGINAL Horner multiply degree0 := mul(2, 2)

After

Newton ORIGINAL step fprime ORIGINAL Horner multiply degree0 = 4

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S012

S014 · calculation

Before

Newton ORIGINAL step fprime ORIGINAL Horner add coefficient0 := sum(4, 0)

After

Newton ORIGINAL step fprime ORIGINAL Horner add coefficient0 = 4

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S013

S015 · calculation

Before

Newton ORIGINAL step ORIGINAL f over fprime := div(-12, 4)

After

Newton ORIGINAL step ORIGINAL f over fprime = -3

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S014

S016 · calculation

Before

Newton ORIGINAL step ORIGINAL tangent zero update := sub(2, -3)

After

Newton ORIGINAL step ORIGINAL tangent zero update = 5

Conditions: none

Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.

Step identifiers and dependencies

Rule: exact_rational_arithmetic · Uses: G001, S015

S017 · implies

Before

source roles = [Newton ORIGINAL step, [-16, 0, 1], [0, 2], 2]

After

derived = [-12, 4, updated, 5]

Conditions: none

Evaluate BOTH f and f_prime completely,then test f=0 FIRST.An exact root stops even at slope0,without0/0.Only a nonroot requires nonzero slope;the tangent-line zero solves z=x-f/f_prime.

Step identifiers and dependencies

Rule: Newton_EACH_f_AND_fprime_ROOT_FIRST_then_nonzero_derivative_division · Uses: G001, S016

Reverse checks

  • S017 · premise_and_result_audit — Reverse-check complete original data,operands and premises;finite checks,conditional reasoning,formal proof and publication authority remain distinct.
  • S016 · premise_and_result_audit — Recompute Newton ORIGINAL step ORIGINAL tangent zero update with exact rational arithmetic, not rounded decimals.
  • S015 · premise_and_result_audit — Recompute Newton ORIGINAL step ORIGINAL f over fprime with exact rational arithmetic, not rounded decimals.
  • S014 · premise_and_result_audit — Recompute Newton ORIGINAL step fprime ORIGINAL Horner add coefficient0 with exact rational arithmetic, not rounded decimals.
  • S013 · premise_and_result_audit — Recompute Newton ORIGINAL step fprime ORIGINAL Horner multiply degree0 with exact rational arithmetic, not rounded decimals.
  • S012 · premise_and_result_audit — Recompute Newton ORIGINAL step fprime ORIGINAL Horner add coefficient1 with exact rational arithmetic, not rounded decimals.
  • S011 · premise_and_result_audit — Recompute Newton ORIGINAL step fprime ORIGINAL Horner multiply degree1 with exact rational arithmetic, not rounded decimals.
  • S010 · premise_and_result_audit — Recompute Newton ORIGINAL step f ORIGINAL Horner add coefficient0 with exact rational arithmetic, not rounded decimals.
  • S009 · premise_and_result_audit — Recompute Newton ORIGINAL step f ORIGINAL Horner multiply degree0 with exact rational arithmetic, not rounded decimals.
  • S008 · premise_and_result_audit — Recompute Newton ORIGINAL step f ORIGINAL Horner add coefficient1 with exact rational arithmetic, not rounded decimals.
  • S007 · premise_and_result_audit — Recompute Newton ORIGINAL step f ORIGINAL Horner multiply degree1 with exact rational arithmetic, not rounded decimals.
  • S006 · premise_and_result_audit — Recompute Newton ORIGINAL step f ORIGINAL Horner add coefficient2 with exact rational arithmetic, not rounded decimals.
  • S005 · premise_and_result_audit — Recompute Newton ORIGINAL step f ORIGINAL Horner multiply degree2 with exact rational arithmetic, not rounded decimals.
  • S004 · premise_and_result_audit — Reverse-check complete original data,operands and premises;finite checks,conditional reasoning,formal proof and publication authority remain distinct.
  • S003 · premise_and_result_audit — Recompute Newton ORIGINAL polynomial ORIGINAL derivative coefficient2 with exact rational arithmetic, not rounded decimals.
  • S002 · premise_and_result_audit — Recompute Newton ORIGINAL polynomial ORIGINAL derivative coefficient1 with exact rational arithmetic, not rounded decimals.
  • S001 · premise_and_result_audit — Reverse-check complete original data,operands and premises;finite checks,conditional reasoning,formal proof and publication authority remain distinct.

Result

([-16, 0, 1], 2, -12, 4, updated, 5, root_test_precedes_division)

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: bc775fb4db9b078e8499a74f031b9ba8f04aa7947a933174b38f558b96b81375
  • candidate record SHA-256: ddef0133a3fb4f3747b15cc5d0ecde872543e2b6a229bbd6135bdc9ff700cd65
  • semantic review receipt SHA-256: 6af367dae24a584f3596525c4953bbc2115343efd68cc9083693eb5c1ef2e683
  • question-first witness SHA-256: 611eb69f3716404b968296a8b0d7d8c61b5ca18129d406f1ff9c7c11e10ffb4e
  • Lean: NOT_RUN · human review: NOT_PERFORMED
Same-source full JSON