| 模型 | 模型答案 | 正确答案 |
|---|---|---|
| 金声玉亮2.0 | D. False, True | D |
| deepseekr1 | The answer is **D**. **Explanation:** - **Statement 1** is **false** because the inverse of a matrix with integer entries and nonzero determinant may not have integer entries (unless the determinant is ±1). For example, a matrix with determinant 2 has an inverse with fractional entries, violating the group requirement. - **Statement 2** is **true** because matrices with integer entries and determinant 1 (the *special linear group* SL(2, ℤ)) form a group: the product of two such matrices has determinant 1, and the inverse (adjugate matrix) also has integer entries with determinant 1. **Answer:** D. False, True |
D |
| gpto1 | D | D |
| GPT-4o | D. False, True | D |
| llama3.1-70B-Instruct | Statement 1 is false because the inverse of a matrix with integer entries may not have integer entries. Statement 2 is true because the inverse of a matrix with integer entries and determinant 1 will also have integer entries and determinant 1. |
D |
| llama3.1-405B-Instruct | A |
D |
| DeepSeek-Coder-V2 | D | D |
| Qwen2-72B-Instruct | D. False, True | D |
| baichuan4 | D. False, True | D |
| doubao | D. False, True The set of 2×2 matrices with integer entries and nonzero determinant is not a group under matrix multiplication because it is not closed. For example, if we multiply two matrices with nonzero determinants, the resulting matrix may have a non-integer entry. However, the set of 2×2 matrices with integer entries and determinant 1 is a group under matrix multiplication as it satisfies all the group properties (closure, associativity, identity, and inverses). |
D |
| minimax | A. True, True Explanation: Statement 1 is true because the set of 2 x 2 matrices with integer entries and nonzero determinant is closed under matrix multiplication, has an identity element (the 2 x 2 identity matrix), each element has an inverse (since the determinant is nonzero, the inverse matrix exists and has integer entries), and matrix multiplication is associative. Statement 2 is also true because the set of 2 x 2 matrices with integer entries and determinant 1 is known as the special linear group SL(2, Z). This set is closed under matrix multiplication, has an identity element (the 2 x 2 identity matrix), each element has an inverse (since the determinant is 1, the inverse matrix exists and has integer entries), and matrix multiplication is associative. |
D |
| kimi | D. False, True Statement 1 is false because the set of 2x2 matrices with integer entries and nonzero determinant is not closed under matrix multiplication. For example, consider two matrices A and B with integer entries and nonzero determinants. The product AB may not have integer entries. Statement 2 is true because the set of 2x2 matrices with integer entries and determinant 1 is closed under matrix multiplication, and it satisfies the group axioms (closure, associativity, identity, and inverses). |
D |
| wenxinyiyan | D Explanation: 1. For the first statement to be true, we need to check if the set of 2x2 matrices with integer entries and nonzero determinant satisfies the group axioms under matrix multiplication. While it is true that the multiplication of two such matrices results in a matrix with integer entries, and the associativity of multiplication holds, the problem arises with the inverse element. Not all 2x2 matrices with integer entries and nonzero determinant have an inverse in this set. For example, consider the matrix $\begin{pmatrix} 2 & 0 \ 0 & 2 \end{pmatrix}$. It has a determinant of 4, which is nonzero, but its inverse $\begin{pmatrix} \frac{1}{2} & 0 \ 0 & \frac{1}{2} \end{pmatrix}$ does not have integer entries. Therefore, the first statement is false. 2. For the second statement, consider the set of 2x2 matrices with integer entries and determinant 1. This set is known as the special linear group $SL_2(\mathbb{Z})$. It can be shown that this set satisfies all the group axioms under matrix multiplication. The multiplication of two such matrices results in a matrix with integer entries and determinant 1 (due to the multiplicativity of determinants). The identity matrix is in this set, and every matrix in this set has an inverse in this set (which can be found using the adjugate matrix and the fact that the determinant is 1). Therefore, the second statement is true. |
D |
| zhipu | D. False, True Explanation: - Statement 1: The set of 2 x 2 matrices with integer entries and nonzero determinant is not a group under matrix multiplication. This set does not satisfy the closure property under multiplication because the product of two matrices with integer entries and nonzero determinants may not have an integer determinant. - Statement 2: The set of 2 x 2 matrices with integer entries and determinant 1 is indeed a group under matrix multiplication. This set forms the special linear group \( SL(2, \mathbb{Z}) \), which satisfies all group axioms including closure, associativity, the existence of an identity element, and the existence of inverses. |
D |
| gpto1 | D | D |
| deepseekv3 | Let's analyze the two statements: **Statement 1**: The set of 2 x 2 matrices with integer entries and nonzero determinant is a group under matrix multiplication. - **False**: For a set to be a group under matrix multiplication, every element must have an inverse within the set. However, while matrices with nonzero determinant have inverses, their inverses may not have integer entries. For example, the matrix \(\begin{pmatrix} 1 & 1 \\ 0 & 1 \end{pmatrix}\) has an inverse \(\begin{pmatrix} 1 & -1 \\ 0 & 1 \end{pmatrix}\), which has integer entries. But the matrix \(\begin{pmatrix} 2 & 0 \\ 0 & 2 \end{pmatrix}\) has an inverse \(\begin{pmatrix} \frac{1}{2} & 0 \\ 0 & \frac{1}{2} \end{pmatrix}\), which does not have integer entries. Therefore, the set is not closed under taking inverses and is not a group. **Statement 2**: The set of 2 x 2 matrices with integer entries and determinant 1 is a group under matrix multiplication. - **True**: The set of 2 x 2 matrices with integer entries and determinant 1 forms the special linear group \(SL(2, \mathbb{Z})\). This set is closed under matrix multiplication, contains the identity matrix, and every element has an inverse within the set (since the inverse of a matrix with determinant 1 also has determinant 1 and integer entries). Therefore, it is a group. **Answer**: D. False, True |
D |