
Hint: Prove <h> is a subset of H and that H is a subset of <h>.
Hope you get it.
Like.
11. Prove that a nonempty subset H of a group G is a subgroup of G if and only if whenever a, b E H, then ab-1 e H
Suppose H is a subset of G is a normal subgroup of index k. Prove that for any a in G, a to the power of k in H. Does this hold without the normality assumption?
#7
7 Prove or disprove: If H is a normal subgroup of G such that H and G/H are abelian, then G is abelian. If G is cyclic, prove that G/H must also be cyclic. 8.
Prove that every subset of N is either finite or countable. (Hint: use the ordering of N.) Conclude from this that there is no infinite set with cardinality less than that of N.
H be an isomorphism. Prove that if G is a cyclic group, then H Exercise 1. Let o: G cyclic group.
2.
problem 3.
Let H be a normal subgroup of a group G and let K be any subgroup of G. Prove that the subset HK of G defined by is a subgroup of G Let G S, H ), (12) (34), (13) (24), (1 4) (23)J, and K ((13)). We know that H is a normal subgroup of S, so HK is a subgroup of S4 by Problem 2. (a) Calculate HK (b) To which familiar group is HK...
Problem 1. Let A be an infinite set such that |Al S INI. Prove A IN (Hint: First prove this for all infinite subsets B CN. Prove the general case by observing there is a bijection between A and some infinite subset of N.)
Problem 1. Let A be an infinite set such that |Al S INI. Prove A IN (Hint: First prove this for all infinite subsets B CN. Prove the general case by observing there is a bijection...
thanks
9. (10 ) Suppose that H and K are distinct subgroups of G of index 2. Prove that HnK is a normal subgroup of G of index 4 and that G/(Hn K) is not cyclic. (Hint. Use the 2nd Isomorphism Theorem)
9. (10 ) Suppose that H and K are distinct subgroups of G of index 2. Prove that HnK is a normal subgroup of G of index 4 and that G/(Hn K) is not cyclic. (Hint. Use the...
31 (a) If fis integrable, prove that fa is integrable. Hint: Given e>0, let h and k be step functions such that h f k and j (k-h) < ε/M, where M is the maximum value of Ik(x) +h(x)]. Then prove that h and k2 are step functions with h' srsk (we may assume that OShSSk since f is integrable if and only if I is-why?), and that I (k2 - h2) <e. Then apply Theorem 3.3. (b) If fand...
1- (2,5+2,5 mark) Consider in GL(2, Q), the subset (a=1 or a=-1),bez Prove that H, with multiplication, is a subgroup of GL(2,Q) a) Is the function b) an homomorphism of groups? Justify your answer 2 (3 marks) Let G be a group and a E G an element of order 12. Find the orders of each of the elements of (a) 3- (1+1,5 marks) Let G be a group such that any non-identity element has order 2. Prove that a)...