Khan/khan-exercises — Issue #11540: Slope of a line - undefined slope
Author: KhanBugz
Created: 2012-01-18 19:13:53+00:00
State: open
Labels: ie8, win7, wrong-or-unclear

Reporter: ffron@verizon.net

I am a teacher and I use this site to review for algebra. I have noticed that the Green line that is supposed to show a vertical line does not show up. My students know that the Green graph that is blank is the undefined one, but they are not learning that a vertical line has an undefined slope. Please fix this.

[slope_of_a_line.html?seed=82&problem=slopes-zero-infinity](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/slope_of_a_line.html?seed=82&problem=slopes-zero-infinity&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/slope_of_a_line.html?seed=82&problem=slopes-zero-infinity&debug&activity=%5B%5D)

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