The Student Room Group
Reply 1
beast
Hello ,
Can someone explain why Z/2Z is a field. I thought Z/2Z represented the even integers. Therefore, I'm not sure why Z/2Z is a field if the elements are not invertible?!! :confused:


2Z is the set of even integers

Z/2Z or Z2 is a field with two elements - you can think of them as Even and Odd if you want, or 0 and 1. Their rules of adding and multiplying are

E+E=E, E+O=O, O+O=E
EE = E, EO=E, OO=O

The additive identity is E, the multiplicative identity is O, and O's inverse is O.
Reply 2
Neapolitan
2Z is the set of even integers

Z/2Z or Z2 is a field with two elements - you can think of them as Even and Odd if you want, or 0 and 1. Their rules of adding and multiplying are

E+E=E, E+O=O, O+O=E
EE = E, EO=E, OO=O

The additive identity is E, the multiplicative identity is O, and O's inverse is O.


Thanks again, you've been a great help! I wish you were my lecturer! :smile: