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Issue 1291: wrongly drawn graph in "introduction to the quadratic equation"
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Reported by leonard....@gmail.com, Sep 7, 2010
http://www.khanacademy.org/video/introduction-to-the-quadratic-equation
at ca 1:40

f(x)=x^2-x-6 results is a parabola whose minimum is at (0.5,-25/4), rather than centered around the f(x) axis as shown in the video.

The commentary indeed brings up that the roots are -2 and 3, but the connection to the location of the global minimum isn't made.

Further, the tip is not at -6 as claimed/drawn in the video, but at -25/4. The wrong conclusion on the location of the tip in the video is reached by assuming the minimum is at x=0 rather than the actual x=0.5: "I know it goes through -6 because when x is 0, f(x) is -6".

Sep 7, 2010
#1 sri...@gmail.com
(No comment was entered for this change.)
Status: Accepted
Labels: Component-Videos
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