Tariq1d ago

My brain's not working.

Is the multiplicative inverse of 1 modulo n always 1, and nothing else?

Of course 1*1=1 ... but I'm doubting myself and wondering if modulo arithmetic opens other possibilities.

#maths #numbertheory

Show threadMike McCoy
@rzeta0 yes. Suppose x is a multiplicative inverse of 1, that is x*1=1. But 1 is the identity so x*1=x. Thus, x=1.
Apr 11 at 2:58pmWeb
Show threadRefurio Anachro1d ago

As @mbmccoy showed, something has to give. Or you could look at a map F->G where multiple values in F are mapped to 1 in G. For example, map some roots of unity to 1.

@rzeta0

Show threadTariq1d ago

@mbmccoy

thanks, this is reassuring !