Khan/khan-exercises — Issue #12066: Dividing complex numbers - Error in explanaition
Author: KhanBugz
Created: 2012-01-25 06:40:52+00:00
State: open
Labels: firefox, other

Reporter: bbb.stocken@gmail.com

When multiplying the nominator (2) with the complex conjugate (-1+3i) of the denominator the sign of the imaginary part changes from + to -. A few steps later in the explanation it changes back again so the final solution is correct. It's just the explanation that confuses things.

[dividing_complex_numbers.html?seed=101&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/dividing_complex_numbers.html?seed=101&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/dividing_complex_numbers.html?seed=101&problem=0&debug&activity=%5B%5B%22hint-activity%22%2C%220%22%2C47%5D%2C%5B%22hint-activity%22%2C%220%22%2C52%5D%2C%5B%22incorrect-activity%22%2C%22%5B%5C%22-1%2F5%5C%22%2C%5C%223%2F10%5C%22%5D%22%2C133%5D%2C%5B%22hint-activity%22%2C%220%22%2C6%5D%2C%5B%22hint-activity%22%2C%220%22%2C24%5D%2C%5B%22incorrect-activity%22%2C%22%5B%5C%22-1%2F5%5C%22%2C%5C%223%2F5%5C%22%5D%22%2C32%5D%2C%5B%22hint-activity%22%2C%220%22%2C16%5D%2C%5B%22hint-activity%22%2C%220%22%2C76%5D%2C%5B%22hint-activity%22%2C%220%22%2C279%5D%2C%5B%22correct-activity%22%2C%22%5B%5C%22-0.2%5C%22%2C%5C%220.6%5C%22%5D%22%2C477%5D%5D)

[["-1/5","3/10"],["-1/5","3/5"],["-0.2","0.6"]]

Mozilla/5.0 (X11; Linux i686; rv:9.0) Gecko/20100101 Firefox/9.0

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