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# modulus watch

1. (Original post by man111111)
why do you multiply x-2 with -1
By definition of we have for . Clearly, when you're talking about the interval this is just a subinterval of .

Otherwise, you can just sketch (or imagine) the graph of . You should know it has something to do with and it is precisely the fact that for we have that portion of the graph equal to
2. (Original post by RDKGames)
By definition of we have for . Clearly, when you're talking about the interval this is just a subinterval of .

Otherwise, you can just sketch (or imagine) the graph of . You should know it has something to do with and it is precisely the fact that for we have that portion of the graph equal to
3. (Original post by man111111)
I meant to write 0<x<1. The post applies.
4. (Original post by man111111)
why do you multiply x-2 with -1
Look. The only thing you really need to know about modulus is that (*)

So, if someone says |x-2| = 2-x, the reason is going to be because x-2 < 0 (and then using (*)).

The fact that you keep asking "why has ... been multiplied by -1"? makes me think you are not understanding the fundamental definition (*).

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