问题


There is a single choice question about abstract algebra. Answer the question by replying A, B, C or D.
Question: If (G, .) is a group such that (ab)^-1 = a^-1b^-1, for all a, b in G, then G is a/an
A. commutative semi group
B. abelian group
C. non-abelian group
D. None of these
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

B. abelian group

Explanation:

If (G, .) is a group such that (ab)^-1 = a^-1b^-1, for all a, b in G, then we can show that G is an abelian group.

Recall that in a group, the inverse of a product is the product of the inverses in reverse order, i.e., (ab)^-1 = b^-1a^-1. However, in this case, we are given that (ab)^-1 = a^-1b^-1, which implies that b^-1a^-1 = a^-1b^-1.

Multiplying both sides on the left by a and on the right by b, we get:

ab = ba

This shows that G is an abelian group, i.e., the group operation is commutative.

Therefore, the correct answer is B. abelian group.
B
deepseekr1

The problem states that in a group \( (G, \cdot) \), the inverse of \( ab \) is \( a^{-1}b^{-1} \) for all \( a, b \in G \). Normally, in a group, \( (ab)^{-1} = b^{-1}a^{-1} \). For the given condition to hold, we equate \( b^{-1}a^{-1} = a^{-1}b^{-1} \). Taking the inverse of both sides gives \( ab = ba \), proving that \( G \) is abelian. Since \( G \) is already a group, this satisfies the definition of an abelian group.

**Answer:** B. abelian group
B
gpto1 B B
GPT-4o B. abelian group B
llama3.1-70B-Instruct

B
B
llama3.1-405B-Instruct

B. abelian group

Explanation:

If (G, .) is a group such that (ab)^-1 = a^-1b^-1, for all a, b in G, then we can show that G is an abelian group.

Recall that in a group, the inverse of a product is the product of the inverses in reverse order, i.e., (ab)^-1 = b^-1a^-1. However, in this case, we are given that (ab)^-1 = a^-1b^-1, which implies that b^-1a^-1 = a^-1b^-1.

Multiplying both sides on the left by a and on the right by b, we get:

ab = ba

This shows that G is an abelian group, since the group operation is commutative.

Therefore, the correct answer is B. abelian group.
B
DeepSeek-Coder-V2 B. abelian group B
Qwen2-72B-Instruct B. abelian group B
baichuan4 B B
doubao B

In an abelian group, the group operation is commutative, and it satisfies the property (ab)^-1 = a^-1b^-1. While a commutative semi group doesn't necessarily have inverses. A non-abelian group doesn't have this property for all elements. So the answer is B.
B
minimax B. abelian group

The given condition (ab)^-1 = a^-1b^-1 implies that for any two elements a and b in G, their product ab commutes with its inverse, which means that ab = ba. This is the definition of an abelian group, where the group operation is commutative.
B
kimi B. abelian group B
wenxinyiyan B. abelian group

Explanation:
Given that $(G, \cdot)$ is a group and $(ab)^{-1} = a^{-1}b^{-1}$ for all $a, b \in G$.

We know that for any element $x$ in a group, $x^{-1}$ is the unique element such that $x \cdot x^{-1} = e$ and $x^{-1} \cdot x = e$, where $e$ is the identity element of the group.

Using this property, we have:
$(ab)^{-1} = a^{-1}b^{-1}$
$\Rightarrow (ab)(ab)^{-1} = (ab)(a^{-1}b^{-1})$
$\Rightarrow e = aba^{-1}b^{-1}$

Since $e$ is the identity element, multiplying by $b$ on the right and then by $a$ on the left, we get:
$aba^{-1}b^{-1}b = eb$
$\Rightarrow ab = ba$

This shows that for any two elements $a$ and $b$ in $G$, $ab = ba$, which means $G$ is an abelian group.
B
zhipu The given condition is \((ab)^{-1} = a^{-1}b^{-1}\) for all \(a, b \in G\).

To determine the nature of the group \(G\), let's analyze this condition.

In general, for any group \(G\), the inverse of a product \(ab\) is given by:
\[
(ab)^{-1} = b^{-1}a^{-1}
\]

However, the given condition states:
\[
(ab)^{-1} = a^{-1}b^{-1}
\]

For these two expressions to be equal, we must have:
\[
b^{-1}a^{-1} = a^{-1}b^{-1}
\]

This equality holds if and only if \(a\) and \(b\) commute, i.e., \(ab = ba\) for all \(a, b \in G\).

Therefore, the group \(G\) must be abelian (commutative).

So, the correct answer is:
B. abelian group
B
gpto1 B B
deepseekv3 The given condition is \((ab)^{-1} = a^{-1}b^{-1}\) for all \(a, b \in G\).

In a group \((G, \cdot)\), the inverse of a product \(ab\) is typically \((ab)^{-1} = b^{-1}a^{-1}\). The given condition \((ab)^{-1} = a^{-1}b^{-1}\) implies that \(b^{-1}a^{-1} = a^{-1}b^{-1}\) for all \(a, b \in G\).

Taking inverses of both sides, we get \(ab = ba\) for all \(a, b \in G\). This shows that the group \(G\) is commutative, or abelian.

Therefore, the correct answer is:

**B. abelian group**
B