Proving Every Element in G is a Square Using Factor Groups

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In summary, if G is an Abelian group and H is a subgroup of G where every element in H is a square and every element in G/H is a square, then every element in G is also a square. This can be proven by utilizing the fact that the operation on H is the same as that from G, and that G being Abelian implies that H is also Abelian. By naming an element b as the square root of any element a in G, it can be shown that b b = a, thus proving that every element in G is a square.
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Homework Statement


Suppose that G is an Abelian group and H is a subgroup of G. If every element of H is a square and every element of G/H is a square , prove that every element of G is a square.


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The Attempt at a Solution


Let a and b be elements of G. The ab=ba since G is an abeleian group. If H is a subgroup of G, then doesn't H share the same opperations with G? If so, since every element of in H is a square, then a^2*b^2 =(aa)(bb)=(bb)(aa) since G is abelian, H should be abelian. Therefore , there is an element in G that is a square
 
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If H is a subgroup of G, then indeed the operation on H is the same as that from G. And since G is abelian, so is H. Indeed, there is an element of G that is a square (in fact, any element from G that is in H is a square).
But the question was to prove that every element of G is a square.

You didn't use the information about G/H yet. So let a be any element of G. Now you will want to prove that there exists some element b (or you could very suggestively name it [itex]\sqrt{a}[/itex] such that b b = a. How can you do this?
 

What is a factor group?

A factor group, also known as a quotient group, is a mathematical group that is formed by dividing a larger group by a normal subgroup. It is denoted by G/N, where G is the original group and N is the normal subgroup.

What is the significance of factor groups?

Factor groups are important in group theory as they allow us to classify and study groups by their properties. They also help us understand the structure of a group by breaking it down into smaller, simpler groups.

How do you find the factor group of a given group?

To find the factor group of a given group, first identify a normal subgroup of the group. Then, use the quotient group formula (G/N) to find the factor group. This involves taking the elements of the original group G and dividing them by the elements of the normal subgroup N.

What are some examples of factor groups?

One example of a factor group is the group of integers modulo n, denoted by Z/nZ. Another example is the factor group of a dihedral group, which represents the symmetries of a regular polygon.

How are factor groups related to cosets?

Factor groups and cosets are closely related as cosets are used to define factor groups. A coset is a subset of a group that is obtained by multiplying a fixed element of the group by all elements of a subgroup. Factor groups can be thought of as the set of all cosets of a given normal subgroup.

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