Khan/khan-exercises — Issue #8641: Point slope form - correct answer marked wrong
Author: KhanBugz
Created: 2011-12-14 17:33:04+00:00
State: open
Labels: firefox, leopard, wrong-or-unclear

Reporter: howard@riverrock.org

Since the line passes through (-3,-1) and (3,1) it must be symmetric about the origin and pass through (0,0). Also it clearly has slope 1/3. However, answering (y-0) = 1/3(x-0) (i.e. y = 1/3 x), which works, is graded wrong.

[point_slope_form.html?seed=7&problem=two-points](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/point_slope_form.html?seed=7&problem=two-points&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/point_slope_form.html?seed=7&problem=two-points&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5B%5B%5C%220%5C%22%2C%5C%221%2F3%5C%22%2C%5C%220%5C%22%5D%5D%22%2C43%5D%5D)

[[["0","1/3","0"]]]

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3

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