( A lecture by Peter again ).

Arithmetic congruent mod n.

Addition

Multiplication

How a congruent b mod n is in fact an equivalence relation.

And thus induces a partition of the integers.

Cosets are nZ, 1+nZ, 2+nZ, ... (n-1)+nZ

Addition can be defined on these cosets and then they have a group structure.

The map Z -> nZ is then a homomorphism with 0 as kernel.

( Around min 35 or so I lost interest... I fast forwarded watching minutes here and there, just to make sure there was not introduced anything I did not know already. I hope I am not losing interest in the series all together. We'll see. )

2-2018 Teaching by misleading

2 months ago

## No comments:

## Post a Comment