Khan/khan-exercises — Issue #9206: Equation of a hyperbola - Square root problem
Author: KhanBugz
Created: 2011-12-21 20:04:10+00:00
State: open
Labels: chrome, vista, wrong-or-unclear

Reporter: samthg@gmail.com

As part of the hints on:

http://www.khanacademy.org/exercise/equation_of_a_hyperbola

Part of the process says that:
sqrt(-81+((x+6)^2)*81/49)
is
9+(x+6)*9/7

Ignoring the fact that:
sqrt(a+b) is not equal to sqrt(a)+sqrt(b)

Thanks

[equation_of_a_hyperbola.html?seed=13&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/equation_of_a_hyperbola.html?seed=13&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/equation_of_a_hyperbola.html?seed=13&problem=0&debug&activity=%5B%5B%22hint-activity%22%2C%220%22%2C74%5D%2C%5B%22hint-activity%22%2C%220%22%2C140%5D%2C%5B%22hint-activity%22%2C%220%22%2C150%5D%2C%5B%22hint-activity%22%2C%220%22%2C158%5D%5D)

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Mozilla/5.0 (Windows NT 6.0) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.63 Safari/535.7

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