Prove that the set of complex numbers {1,−1,i,−i} under
multiplication operation is a cyclic group.Find the generators of
cycle
Let R be the ring of Gaussian integers as in Exercise 11, and let I = {a + bi |3 divided a and 3 divides b}.
a. Show that I is an ideal of R.
b. Show that I is not a maximal ideal of R.
Let L: R² --R2 be defined by L([u₁ u₂]) = [u1 + 2u2, 2u¹ - u²] Let S be the natural basis for
R² and let T= ([-1,2],[2,0])
a. Find the matrix representation of [T]}s,t.
b. Find L([1,2[) by using the definition of L. and using the matrix found in (a).
3. Let L: R₂ → R₂ be the linear transformation defined by L ([u¹, u₂]) = [u1, 0]
a. Is [0, 2] in Ker L?
b. Is [2,2] in Ker L?
C. Is [3,0] in range L?
d. Is [ 3,2] in range L?
e. Find Ker L.
£. Find Range L.
Prove that Sn is not solvable for n>4.
Let a and b be integers. Prove that if a∣b, then an∣bn for all positive integers n.
Prove or disprove that the polynomial 21x^3 - 3x^2 + 2x + 9 is irreducible over Z2 , but not over Z3. Justify your answer.
Prove that if a|b and f(a) = f(b), then a and b are associates.
Prove or disprove that in Z[x], the ideal <x> + <3> is a principal ideal.
If A'B + CD' = 0, then prove that:
AB + C'(A' + D') = AB + BD + (BD)' + A'C'D.