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# quick modulus question watch

1. I was looking through a solution to a question and found this:

what are the rules for modulus functions? wouldn't the norm be to separate the fraction using |w+1-3i|-|2| rather than multiplying by 2?

slightly confused, sorry if its a trivial question :/
2. Both sides of the equation have been multiplied by 2? I'm not sure what you mean by "separate the fraction using |w+1-3i| - |2|"?

EDIT: And what do you mean about the "rules for modulus functions"?. In general, , but
3. Basically the modulus function turns something negative into a positive:- if you did the modulus of '-1' you would get '1'. Since 2 is already a positive number the modulus brackets can be ignored and you just re-arrange the equation as normal.

This only changes when you have got a variable though, as there are different possible solutions then, depending upon the size of the variable.
4. (Original post by ashleyb123)
I was looking through a solution to a question and found this:

what are the rules for modulus functions? wouldn't the norm be to separate the fraction using |w+1-3i|-|2| rather than multiplying by 2?

slightly confused, sorry if its a trivial question :/
I think you're confusing this with the idea of the argument of the quotient of two complex numbers. i.e. , where and is chosen to ensure that the resulting argument follows whichever convention you are following i.e. the -convention, -convention etc.

A modulus is just a real number so it's fine to just multiply both sides by it.

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