{"schema_version":"ocme-site-results-v1","locale":"en","page_type":"derivations","facts":{"questions":36000,"reviewed":36000,"display_candidates":0,"knowledge":302,"guides":299,"paths":59,"batches":360,"families":1441,"atlas":302,"core":80,"evidence":9,"formal_evidence":5,"formal_subjects":4,"lean_files":6,"lean_toolchain":"leanprover/lean4:v4.30.0","question_state":"candidate","english_state":"ai_candidate","question_Lean":"NOT_RUN","canonical_truth_promotion":false},"filters":{"q":"mko-bisection-method"},"kind":"guides","total":1,"pages":1,"page":1,"entries":[{"id":"derivation-mko-bisection-method-01","title":{"zh-Hant":"二分法：四步 bracket 更新、不變量與根存在的獨立責任","en":"Bisection: four bracket updates, the invariant and the separate proof obligation for root existence"},"summary":{"zh-Hant":"對 f(x)=x²−2，從 [1,2] 與所提供的端點符號 f(1)<0、f(2)>0 出發，依所提供的中點符號執行四步二分，追蹤 bracket；證明「端點異號且 a<b」是不變量、n 步後寬度為 1/2^n、在每次所需符號可取得且更新有效的延伸執行中，寬度停止準則必在有限步內終止；再證明這些 bracket 資料本身不證明有根，並另外引用中間值定理，對連續的 f 得出最終 bracket 內有根。","en":"For f(x)=x²−2, start from [1,2] with the supplied endpoint signs f(1)<0 and f(2)>0, run four bisection steps with the supplied midpoint signs and trace the brackets; prove that 'opposite endpoint signs and a<b' is an invariant, that the width after n steps is 1/2^n, and that, in an extended run with every needed sign available and effective updates, a width-based stopping rule terminates after finitely many steps; then show that the bracket data alone do not prove a root exists, and separately cite the intermediate value theorem to conclude, for the continuous f, that the final bracket contains a root."},"mko_ids":["mko-bisection-method"]}],"title":"Concept derivation guides"}