{"action":"opened","issue":{"url":"https://api.github.com/repos/dart-lang/sdk/issues/26261","repository_url":"https://api.github.com/repos/dart-lang/sdk","labels_url":"https://api.github.com/repos/dart-lang/sdk/issues/26261/labels{/name}","comments_url":"https://api.github.com/repos/dart-lang/sdk/issues/26261/comments","events_url":"https://api.github.com/repos/dart-lang/sdk/issues/26261/events","html_url":"https://github.com/dart-lang/sdk/issues/26261","id":148331019,"number":26261,"title":"Please, clarify the conformance of math functions","user":{"login":"alsemenov","id":4629015,"avatar_url":"https://avatars.githubusercontent.com/u/4629015?v=3","gravatar_id":"","url":"https://api.github.com/users/alsemenov","html_url":"https://github.com/alsemenov","followers_url":"https://api.github.com/users/alsemenov/followers","following_url":"https://api.github.com/users/alsemenov/following{/other_user}","gists_url":"https://api.github.com/users/alsemenov/gists{/gist_id}","starred_url":"https://api.github.com/users/alsemenov/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/alsemenov/subscriptions","organizations_url":"https://api.github.com/users/alsemenov/orgs","repos_url":"https://api.github.com/users/alsemenov/repos","events_url":"https://api.github.com/users/alsemenov/events{/privacy}","received_events_url":"https://api.github.com/users/alsemenov/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-04-14T11:29:39Z","updated_at":"2016-04-14T11:29:39Z","closed_at":null,"body":"The description for `dart:math` package ( https://api.dartlang.org/stable/1.15.0/dart-math/dart-math-library.html ) reads:\r\n>Mathematical constants and functions, plus a random number generator.\r\n\r\nPlease, clarify the level of conformance of provided math functions.\r\n\r\n1. How the used algorithms and calculated results correspond with certain published algorithms? \r\n\r\n2. Should the functions return the same results across all supported platforms?\r\n\r\nFor example, the following test\r\n```dart\r\nimport \"dart:math\" as Math;\r\n\r\nmain() {\r\n  print(Math.acos(-0.74603174603174605000));\r\n}\r\n```\r\nproduces different results on linux `2.4128792028463875` and windows `2.412879202846388` platforms\r\nIs it normal behavior?\r\n"}}