Question

In: Advanced Math

Let f: Q8 to D8 be a homomorphism from the quaternion Q8 to the dihedral group...

Let f: Q8 to D8 be a homomorphism from the quaternion Q8 to the dihedral group D8 of order 8. Suppose that f (i) = rs and f( j) = r^2.

(a) Find f (k) and f(-k) (expressed in standard form r^i*s^i for suitable i and j) ·

(b) List the elements in the kernel of f in standard form.

(c) The quotient group Q8/ker(f) is isomorphic to which one of the groups C2, C4 or C2xC2    why?

Solutions

Expert Solution

Problem (a)

Problem (b)

As we have seen above,

So, are not in the kernel.

Now,

And

So, are also not in the kernel.

Thus, the only elements in the kernel are

Problem (c)

Now, if you quotient by , that means is same as

So, and

And also,

So, it is an abelian group of order , namely where

Therefore,


Related Solutions

Let f be a group homomorphism from a group G to a group H If the...
Let f be a group homomorphism from a group G to a group H If the order of g equals the order of f(g) for every g in G must f be one to one.
Let D8 be the group of symmetries of the square. (a) Show that D8 can be...
Let D8 be the group of symmetries of the square. (a) Show that D8 can be generated by the rotation through 90◦ and any one of the four reflections. (b) Show that D8 can be generated by two reflections. (c) Is it true that any choice of a pair of (distinct) reflections is a generating set of D8? Note: What is mainly required here is patience. The first important step is to set up your notation in a clear way,...
what are the left cosets of the dihedral group d2n ?and let the subgroup are reflection?
what are the left cosets of the dihedral group d2n ?and let the subgroup are reflection?
Let D10 denote the dihedral group of the hexagon. Thus, D10 is generated by r and...
Let D10 denote the dihedral group of the hexagon. Thus, D10 is generated by r and f with r10=f2=1 and fr=r-1f=r9f (a) Show that D10 has a subgroups N and M such that i. N ∼= D5 (isomorphic to D5) ii. M is a cyclic subgroup group of order 2 iii. N ∩ M = {e} iv. N and M are each normal in D10 v. Every element in g ∈ D10 is a product g = nm of elements...
Let φ : G1 → G2 be a group homomorphism. (abstract algebra) (a) Suppose H is...
Let φ : G1 → G2 be a group homomorphism. (abstract algebra) (a) Suppose H is a subgroup of G1. Define φ(H) = {φ(h) | h ∈ H}. Prove that φ(H) is a subgroup of G2. (b) Let ker(φ) = {g ∈ G1 | φ(g) = e2}. Prove that ker(φ) is a subgroup of G1. (c) Prove that φ is a group isomorphism if and only if ker(φ) = {e1} and φ(G1) = G2.
describe group homomorphisms from Q8 into Z8.
describe group homomorphisms from Q8 into Z8.
Let f : G → G′ be a surjective homomorphism between two groups, G and G′,...
Let f : G → G′ be a surjective homomorphism between two groups, G and G′, and let N be a normal subgroup of G. Prove that f (N) is a normal subgroup of G′.
(a) What is a group homomorphism? (b) What is a group representation? What is the dimension of a group representation?
(a) What is a group homomorphism? (b) What is a group representation? What is the dimension of a group representation?(c) What is an irreducible group representation? (d) What is a unitary group representation? Give an example. Why are such representations important in quantum mechanics?
Let F be a finite field. Prove that the multiplicative group F*,x) is cyclic.
Let F be a finite field. Prove that the multiplicative group F*,x) is cyclic.
Find all homomorphism (1) f : z -> z_5 (2) f: z_5 -> z_5 (3) f:...
Find all homomorphism (1) f : z -> z_5 (2) f: z_5 -> z_5 (3) f: z_3 -> S_3
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT