Sal Khan responds to critic 
Can anyone weigh in on their differing arguments regarding the definition of slope? I am not a maths expert by any means, but am genuinely curious who is correct here. Or is this a matter of one being technically correct versus the other being correct in practice?(Cross posted from the original thread because I genuinely would like an opinion more informed than my own and the totally unhelpful "conclusion" provided by Valerie Strauss.)*Edit, I missed that he (Khan) posted a video defending his definition http://www.youtube.com/watch?v=TNaQJjLAhkI