{"action":"closed","issue":{"number":3890,"created_at":"2011-10-06T06:35:36Z","pull_request":{"diff_url":null,"patch_url":null,"html_url":null},"body":"Reporter: billrenner@gmail.com\n\nA problem in this quiz set offers an incorrect answer.  Problem:\n\nf(x) = sqrt(x−1) / (x2+8x+15)\n\nFind the domain.\n\nx >= 1 based on the numerator\n\nfactor the denominator into (x+3)(x+5).  x cannot equal -3 or -5, either of which will zero the denominator.\n\nOffered answers are only x >= 1.  No consideration given to the divide by zero possibility.\n\n[domain_of_a_function.html?seed=120&problem=sqrt-poly-frac](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/domain_of_a_function.html?seed=120&problem=sqrt-poly-frac)\n\n    [\"None of the above.\",\"<code style=\\\"display: none;\\\">\\\\{ \\\\, x \\\\in \\\\RR \\\\mid x \\\\geq1\\\\, \\\\}</code>\"]\n\nMozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.23) Gecko/20110920 Firefox/3.6.23 SearchToolbar/1.2\n\nMathJax is loaded, ready, queue length: 0\n\n","comments":0,"title":"Domain of a function - Problem with an incorrect answer","updated_at":"2011-10-20T23:20:52Z","url":"https://api.github.com/repos/Khan/khan-exercises/issues/3890","id":1831365,"assignee":null,"milestone":null,"closed_at":"2011-10-20T23:20:52Z","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","id":924247,"login":"KhanBugz"},"html_url":"https://github.com/Khan/khan-exercises/issues/3890","labels":[{"name":"firefox","url":"https://api.github.com/repos/Khan/khan-exercises/labels/firefox","color":"e102d8"},{"name":"win7","url":"https://api.github.com/repos/Khan/khan-exercises/labels/win7","color":"ededed"}],"state":"closed"},"legacy":{"number":3890,"action":"closed","issue":1831365}}