Khan/khan-exercises — Issue #5238: Kinematic equations - quadratic equation results in ambiguity
Author: KhanBugz
Created: 2011-10-31 00:18:57+00:00
State: open
Labels: firefox

After solving the quadratic equation, two possible values for time are found:

16.0861571914519 and 16.7000861947915

Only 16.7 is accepted as correct.

Why?

[kinematic_equations.html?seed=195&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/kinematic_equations.html?seed=195&problem=0&debug)

[["16.1","s"],["16.7","s"]]

Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1

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