{"issue":{"state":"closed","pull_request":{"diff_url":null,"html_url":null,"patch_url":null},"user":{"avatar_url":"https://secure.gravatar.com/avatar/96ea3904626fe17bec2152ee31cee0cd?d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-140.png","gravatar_id":"96ea3904626fe17bec2152ee31cee0cd","url":"https://api.github.com/users/KhanBugz","login":"KhanBugz","id":924247},"milestone":null,"updated_at":"2011-11-05T02:59:42Z","labels":[{"name":"firefox","color":"e102d8","url":"https://api.github.com/repos/Khan/khan-exercises/labels/firefox"},{"name":"vista","color":"ededed","url":"https://api.github.com/repos/Khan/khan-exercises/labels/vista"}],"assignee":null,"comments":1,"closed_at":"2011-11-05T02:59:42Z","url":"https://api.github.com/repos/Khan/khan-exercises/issues/5592","body":"Reporter: seppo.kangas@gmail.com\n\nthe problem asks for tan^-1(-1) which corresponds to the angle 3pi/4 + n*pi. This is 135 + n*180 in degrees. 135 degrees wasn't accepted as a solution but instead the angle -45 deg was required. Either both should be accepted or then the preference for the convention of the smaller absolute value clearly stated.\n\n[trigonometry_challenge.html?seed=96&problem=7 (inverse_trig_functions)](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/trigonometry_challenge.html?seed=96&problem=7&debug)\n\n    [\"135 deg\",\"-45\",\"-45 deg\"]\n\nMozilla/5.0 (Windows NT 6.0; rv:7.0.1) Gecko/20100101 Firefox/7.0.1\n\nMathJax is loaded, ready, queue length: 0\n\n","html_url":"https://github.com/Khan/khan-exercises/issues/5592","number":5592,"title":"Trigonometry challenge - trigonometry problem doesn't accept correct solution","id":2148022,"created_at":"2011-11-04T20:26:31Z"},"action":"created","comment":{"user":{"avatar_url":"https://secure.gravatar.com/avatar/91e2e1c5cda628431f62bdaa980b8cd6?d=https://a248.e.akamai.net/assets.github.com%2Fimages%2Fgravatars%2Fgravatar-140.png","gravatar_id":"91e2e1c5cda628431f62bdaa980b8cd6","url":"https://api.github.com/users/beneater","login":"beneater","id":1017630},"updated_at":"2011-11-05T02:59:42Z","url":"https://api.github.com/repos/Khan/khan-exercises/issues/comments/2638649","body":"Question asks for the \"principal value\" which is defined as being in the first or fourth quadrant.","id":2638649,"created_at":"2011-11-05T02:59:42Z"}}