Marquette University

Department of Mathematical and Statistical Sciences

Wim Ruitenburg's Spring 2024 MATH/SSC 4/5121-101. Recommended homeworks

Last updated: 29 April 2024
Comments and suggestions: Email   wim.ruitenburg@marquette.edu

29 April Section 22.4 : If you were to factorize polynomial x^(3^6) - x = x^729 - x over Z_3 into monic prime factors, how
many prime factors would there be of degree 1, of degree 2, etc?
If you were to factorize polynomial x^(3^6) - x = x^729 - x over GF(3^2) into monic prime factors, how
many prime factors would there be of degree 1, of degree 2, etc?
26 April Section 22.4 (page 308): 17, 24
24 April Section 22.4: Factorize X^4 - X into primes over GF(4), where GF(4) has an element \alpha such that \alpha^2 + \alpha + 1 = 0.
Factorize X^8 - X into primes over GF(4), where GF(4) has an element \alpha such that \alpha^2 + \alpha + 1 = 0.
Factorize X^16 - X into primes over GF(4), where GF(4) has an element \alpha such that \alpha^2 + \alpha + 1 = 0.
22 April Section 22.4 (page 308): 20 (needs counting), 21, 22, 23
19 April Section 22.4 (page 308): 14, 15 (tricky, a simple proof when the size is even, and
a pigeon hole principle when the size is odd), 16, 18
Homeworks for points are in this color
Factorize polynomial x^(2^6) - x = x^64 - x over Z_2 into monic prime factors. How
many prime factors are here of degree 1, of degree 2, etc?
If you were to factorize polynomial x^(2^15) - x = x^32768 - x over Z_2 into monic prime factors, how
many prime factors would there be of degree 1, of degree 2, etc?
If you were to factorize polynomial x^(3^8) - x = x^6561 - x over Z_3 into monic prime factors, how
many prime factors would there be of degree 1, of degree 2, etc?
Due date Monday 29 April.
17 April Section 22.4 (page 308): 3, 7b
15 April Section 22.4 (page 308): 7bcd, 8, 12
12 April Section 22.4 (page 308): 5, 6, 7a
10 April Section 22.4 (page 308): 1ab, 2, 4
8 April Section 21.5 (page 293): 11, 12 (not), 13
Find the splitting field of p(x) = x^4 - 2 over the field of rationals Q.
5 April Section 21.5 (page 293): 5, 9, 10
Find the dimension [E:F] where F equals the rationals Q and E equals Q(\sqrt{1 + \sqrt{2}}), and
give a basis of the vector space E over F.
3 April Section 21.5 (page 293): 3cd, 4a
25 March Section 21.5 (page 293): 2dgh, 3ab
22 March Section 21.5 (page 293): 1cde, 2ab
20 March Section 21.5 (page 293): 1ab
Section 20.5 (page 272): 16, 17
18 March Section 20.5 (page 272): 4, 5, 11, 15
8 March Section 20.5 (page 272): 3, 7
6 March Section 20.5 (page 272): 1, 2, 4, 5
4 March Section 18.4 (page 248): 16 (factorize 6), 17 (no)
Homeworks for points are in this color
Factor integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13 into irreducibles over the Gaussian integers Z[i].
Show that 2 + \sqrt{2} divides 2 + 3 \sqrt{2} in Z[\sqrt{2}] by computing the quotient in Z[\sqrt{2}].
Factor integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and 13 into irreducibles over the Euclidean integral domain Z[i \sqrt{2}].
Due date Wednesday 20 March (after Spring break).
1 March Section 18.4 (page 248): 1, 2, 18 (tricky, but actually easy)
28 February Section 18.4 (page 248): 11d, 14, 15
26 February Section 18.4 (page 248): 11b (very difficult), 11c, 12, 13
23 February Section 18.4 (page 248): 16, 17
21 February Section 18.4 (page 248): 10, 11a, 13
19 February Section 18.4 (page 248): 4, 5, 9
14 February Section 18.4 (page 248): 1, 2
12 February Section 17.5 (page 231): 25bce, 26, 27
9 February Section 17.5 (page 231): 18, 20, 21 (easy if F is infinite), 24
7 February Section 17.5 (page 231): 12, 14 (tricky), 15 (tricky)
5 February Section 17.5 (page 231): 6, 7, 9, 10
2 February Section 17.5 (page 231): 4a, 5bd
31 January Section 17.5 (page 231): 2cf, 3c
Section 16.7 (page 213): 36, 37
29 January Section 16.7 (page 213): 29, 30 (disprove), 33
Homeworks for points are in this color
For which positive integers n has the finite ring Z_n non-zero nilpotent elements, and why?
In such cases, describe the ideal of nilpotent elements.
Due date Friday 9 February.
26 January Section 16.7 (page 213): 27, 28
24 January Section 16.7 (page 213): 25, 26
22 January Section 16.7 (page 213): 7, 8, 11, 13a, 16, 24
19 January Section 16.7 (page 213): 4, 5, 6
An axiomatization of groups is at 180923_aata_grp.pdf
17 January Section 16.7 (page 213): 1, 2, 3