Khan/khan-exercises — Issue #10970: Point slope form - Ambigous answer for "Point slope form"
Author: KhanBugz
Created: 2012-01-11 21:14:17+00:00
State: open
Labels: firefox, win7, wrong-or-unclear

Reporter: dify.ltd@gmail.com

The problem says: A line passes through both (3,−3) and (5,−5). Express the equation of the line in point slope form.

And the accepted solution says:
(y−−3)=−1(x−3)
OR
(y−−5)=−1(x−5)

However in my opinion also the following should be a valid solution:

(y−0)=−1(x−0)

In fact for this input any integer is a solution:

(y−-I)=−1(x−I)

[point_slope_form.html?seed=50&problem=two-points](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/point_slope_form.html?seed=50&problem=two-points&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/point_slope_form.html?seed=50&problem=two-points&debug&activity=%5B%5B%22incorrect-activity%22%2C%22%5B%5B%5C%220%5C%22%2C%5C%22-1%5C%22%2C%5C%220%5C%22%5D%5D%22%2C82%5D%2C%5B%22hint-activity%22%2C%220%22%2C4%5D%2C%5B%22hint-activity%22%2C%220%22%2C4%5D%2C%5B%22hint-activity%22%2C%220%22%2C4%5D%5D)

[[["0","-1","0"]]]

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:9.0.1) Gecko/20100101 Firefox/9.0.1

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