Homework assignments for Math 28b, Spring 2003
Problem Set 1. Due Thursday, Jan. 23
- Page 234-237: 3,6, 12,28,40,48
- Show that the only units in Z[i] are 1,i,-1 and -i.
- Find an invertible element in Z[√7] other than 1 or -1. (That's supposed to be the square root of 7 in the brackets.)
- Let B consist of all matrices
where a and b are real numbers. Is B a subring of M2(R)?
Is B a field? Explain.