{"id":1155,"date":"2017-12-06T22:56:21","date_gmt":"2017-12-06T21:56:21","guid":{"rendered":"http:\/\/xmau.com\/wp\/ilpost\/?p=1155"},"modified":"2017-12-06T22:56:21","modified_gmt":"2017-12-06T21:56:21","slug":"approssimazioni-pandigitali-pillole","status":"publish","type":"post","link":"https:\/\/xmau.com\/ilpost\/2017\/12\/06\/approssimazioni-pandigitali-pillole\/","title":{"rendered":"Approssimazioni pandigitali [Pillole]"},"content":{"rendered":"<p>Non ci crederete, ma il numero pandigitale (che usa cio\u00e8 tutte le cifre da 1 a 9 senza ripetizioni: se volete anche lo 0 basta sommarglielo&#8230;)<br \/>\n<img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"1159\" data-permalink=\"https:\/\/xmau.com\/ilpost\/2017\/12\/06\/approssimazioni-pandigitali-pillole\/e-approx\/\" data-orig-file=\"https:\/\/i0.wp.com\/xmau.com\/ilpost\/wp-content\/uploads\/sites\/5\/2017\/12\/e-approx.png?fit=183%2C42&amp;ssl=1\" data-orig-size=\"183,42\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"e-approx\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/xmau.com\/ilpost\/wp-content\/uploads\/sites\/5\/2017\/12\/e-approx.png?fit=183%2C42&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/xmau.com\/wp\/ilpost\/wp-content\/uploads\/sites\/4\/2017\/12\/e-approx.png?resize=183%2C42\" alt=\"\" width=\"183\" height=\"42\" class=\"aligncenter size-full wp-image-1159\" \/><br \/>\n\u00e8 un&#8217;approssimazione della costante matematica <i>e<\/i> (il numero di Nepero, 2,71828&#8230;) corretta nelle prime 18457734525360901453873570 cifre decimali! <\/p>\n<p>D&#8217;accordo, ho barato. No, l&#8217;approssimazione \u00e8 davvero cos\u00ec vicina al valore reale di <i>e<\/i>, ed \u00e8 stata scoperta da tale R. Sabey nel 2004, come potete leggere <a href=\"http:\/\/mathworld.wolfram.com\/eApproximations.html\">su MathWorld<\/a>. Il punto \u00e8 che come certo saprete <i>e<\/i> \u00e8 il limite per <i>n<\/i> tendente all&#8217;infinito di (1+1\/<i>n<\/i>)<sup><i>n<\/i><\/sup>, e quindi creando un <i>n<\/i> molto grande ci si avvicina facilmente al risultato voluto. <\/p>\n<p>Pi\u00f9 interessante, anche se meno precisa visto che arriva solo a 17 cifre decimali, \u00e8 la seguente approssimazione di &pi; trovata da G. W. Barbosa e sempre raccontata da <a href=\"http:\/\/mathworld.wolfram.com\/PiApproximations.html\">MathWorld<\/a>:<br \/>\n<img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"1160\" data-permalink=\"https:\/\/xmau.com\/ilpost\/2017\/12\/06\/approssimazioni-pandigitali-pillole\/pi-approx\/\" data-orig-file=\"https:\/\/i0.wp.com\/xmau.com\/ilpost\/wp-content\/uploads\/sites\/5\/2017\/12\/pi-approx.png?fit=433%2C77&amp;ssl=1\" data-orig-size=\"433,77\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"pi-approx\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/xmau.com\/ilpost\/wp-content\/uploads\/sites\/5\/2017\/12\/pi-approx.png?fit=433%2C77&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/xmau.com\/wp\/ilpost\/wp-content\/uploads\/sites\/4\/2017\/12\/pi-approx-300x53.png?resize=300%2C53\" alt=\"\" width=\"300\" height=\"53\" class=\"aligncenter size-medium wp-image-1160\" srcset=\"https:\/\/i0.wp.com\/xmau.com\/ilpost\/wp-content\/uploads\/sites\/5\/2017\/12\/pi-approx.png?resize=300%2C53&amp;ssl=1 300w, https:\/\/i0.wp.com\/xmau.com\/ilpost\/wp-content\/uploads\/sites\/5\/2017\/12\/pi-approx.png?w=433&amp;ssl=1 433w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>A che serve tutto questo? A nulla, ovviamente.<br \/>\n(Per i curiosi, ho creato le formule matematiche con <a href=\"http:\/\/www.sciweavers.org\/free-online-latex-equation-editor\">iTex2img<\/a>)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>come scrivere una costante matematica (o quasi) in modo creativo<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"activitypub_content_warning":"","activitypub_content_visibility":"","activitypub_max_image_attachments":4,"activitypub_interaction_policy_quote":"anyone","activitypub_status":"","footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[60],"class_list":["post-1155","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-approssimazioni"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/phh2yP-iD","jetpack-related-posts":[{"id":777,"url":"https:\/\/xmau.com\/ilpost\/2016\/05\/13\/quante-cifre-di-pi-greco-ci-servono-davvero-pillole\/","url_meta":{"origin":1155,"position":0},"title":"Quante cifre di pi greco ci servono davvero? 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