# Consider Z4 ({0, 1, 2, 3} mod 4) and GF (4) (also known as GF(2^2)).

1. Nov 7, 2006

### krispiekr3am

(a) Is (Z4, +) a group? Is (Z4, +, *) a ring? Explain.
(b) Is Z4 a field, in other words, does every integer in Z4 have a multiplicative inverse?
(c) Generate the addition table and multiplication table of GF(4).

can someone help me. i am clueless?

2. Nov 7, 2006

### Hurkyl

Staff Emeritus
Have you had any thoughts on the problem?

3. Nov 8, 2006

### HallsofIvy

Staff Emeritus
In particular, have you written out the addition and multiplication tables for Z4?