


1. Let f(x) group, and explicitly how each element of the group acts on the splitting field. Justify your claim a) (5&#...
Determine the Galois group (up to isomorphism) of each of the following polynomials over Q (that is, find the Galois group of the splitting field othe polynomial over Q) Also, draw the complete lattice of subfeilds of the splitting field. Determine the Galois group (up to isomorphism) of each of the following polynomials over Q (that is, find the Galois group of the splitting field othe polynomial over Q) Also, draw the complete lattice of subfeilds of the splitting field.
Part D,E,F,G
10. Let p(x) +1. Let E be the splitting field for p(x) over Q. a. Find the resolvent cubic R(z). b. Prove that R(x) is irreducible over Q. c. Prove that (E:Q) 12 or 24. d. Prove: Gal(E/Q) A4 or S4 e. If p(x) (2+ az+ b)(a2 + cr + d), verify the calculations on page 100 which show that a2 is a root of the cubic polynomial r(x)3-4. 1. f. Prove: r(x) -4z 1 is irreducible in...
5. Let F be a field, and let p(x) ∈ F [x] be a separable, irreducible polynomial of degree 3. Let K be the splitting field of p(x), and denote the roots of p(x) in K by α1, α2, α3. a) (10’) If char(F ) does not equal 2, 3, prove that K = F (α1 − α2).
Exercise 1 Let E, FCC and let E 2F be a field. (a) Without using the primitive element theorem, show that [E : FI < oo if and only if (Hint: Tower law → [F(01, , , , a.) : F1 < oo. For the other direction, use induction on IE、F) (b) Suppose that E F(a Show that E is normal if and only if for every E Flai, . . . , α.) for some on. . . ....
2u-5 8. Let w be a root of f(x) = r +2r - 6 over the field Q. Consider z E Q(w). Find a, b, c, d e Q us + w-2 such that : a + bu + cu2 + du 9. Let E be an extension field of a field F. (1) What does it mean for an element z E E being algebraic over F? (2) What does it mean for an element z EF being transcendental...
8. Let n be a positive integer. The n-th cyclotomic polynomial Ф,a(z) E Z[2] is defined recursively in the following way: 1. Ф1(x)-x-1. 2. If n > 1, then Фп(x)- , (where in the product in the denomina- tor, d runs through all divisors of n less than n). . A. Calculate Ф2(x), Ф4(x) and Ф8(z): . B. n(x) is the minimal polynomial for the primitive n-th root of unity over Q. Let f(x) = "8-1 E Q[a] and ω...
9. Let E be an extension field of a field F. (1) What does it mean for an element z EE being algebraic over F? (2) What does it mean for an element z E E being transcendental over F? (3) Can you find any element r e C such that r is transcendental over Q? (4) Can you prove that if a E E is algebraic over F then (F(a): F] is finite? (5) Can you prove that if...
Let F be a finite field with q elements. a) S -1 for every a*0 in F. how that a-1 either f* 0 or deg(f*)<q, and f* induces the same function on F as f does. function on F, then f=g. b) Let j(X)E F[X]. Show that there exists a polynomial /*(X)EF[X] such that c) Show that if two polynomials f and g, each of degree <g, induce the same
Let F be a finite field with q elements. a)...
Homework 19. Due April 5. Consider the polynomial p(z) = r3 + 21+1. Let F denote the field Q modulo p(x) and Fs denote the field Zs[r] modulo p(x). (i) Prove that p(x) is irreducible over Q and also irreducible over Zs, so that in fact, F and Fs are fields (ii) Calculate 1+2r2-2r + in HF. (iii) Find the multiplicative inverse of 1 +2r2 in F. (iv) Repeat (ii) and (iii) for Fs. (v) How many elements are in...