问题


There is a single choice question about abstract algebra. Answer the question by replying A, B, C or D.
Question: Determine whether the polynomial in Z[x] satisfies an Eisenstein criterion for irreducibility over Q. x^2 - 12
A. Yes, with p=2.
B. Yes, with p=3.
C. Yes, with p=5.
D. No.
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

To apply the Eisenstein criterion for irreducibility, we need to find a prime number $p$ such that the polynomial $f(x) = x^2 - 12$ satisfies the following conditions:

1. $p$ does not divide the leading coefficient of $f(x)$, which is 1.
2. $p$ divides all the other coefficients of $f(x)$, which are 0 and -12.
3. $p^2$ does not divide the constant term of $f(x)$, which is -12.

Let's check the options:

A. $p = 2$: 2 does not divide the leading coefficient 1, but 2 does not divide the constant term -12, so this option does not work.

B. $p = 3$: 3 does not divide the leading coefficient 1, and 3 divides the constant term -12, but $3^2 = 9$ does not divide -12, so this option works!

C. $p = 5$: 5 does not divide the leading coefficient 1, but 5 does not divide the constant term -12, so this option does not work.

D. No: We have found a prime $p = 3$ that satisfies the Eisenstein criterion, so this option is incorrect.

Therefore, the correct answer is:

B. Yes, with p=3.
B
deepseekr1

The polynomial \( x^2 - 12 \) in \( \mathbb{Z}[x] \) is analyzed using the Eisenstein criterion. The coefficients are \( 1 \) (leading term), \( 0 \) (middle term), and \( -12 \) (constant term). For Eisenstein to apply, there must exist a prime \( p \) such that:

1. \( p \) divides all coefficients except the leading term,
2. \( p \) does not divide the leading coefficient,
3. \( p^2 \) does not divide the constant term.

**For \( p = 2 \):**
- \( 2 \) divides \( 0 \) and \( -12 \), satisfying condition 1.
- \( 2 \) does not divide \( 1 \), satisfying condition 2.
- \( 2^2 = 4 \) divides \( -12 \), violating condition 3. Thus, \( p = 2 \) fails.

**For \( p = 3 \):**
- \( 3 \) divides \( 0 \) and \( -12 \), satisfying condition 1.
- \( 3 \) does not divide \( 1 \), satisfying condition 2.
- \( 3^2 = 9 \) does not divide \( -12 \), satisfying condition 3. All conditions are met, so Eisenstein applies with \( p = 3 \).

**For \( p = 5 \):**
- \( 5 \) does not divide \( -12 \), failing condition 1. Thus, \( p = 5 \) fails.

Since \( p = 3 \) satisfies all criteria, the polynomial is irreducible over \( \mathbb{Q} \) by Eisenstein.

**Answer: B**
B
gpto1 B B
GPT-4o D. No. B
llama3.1-70B-Instruct

A
B
llama3.1-405B-Instruct

B. Yes, with p=3.
B
DeepSeek-Coder-V2 D. No. B
Qwen2-72B-Instruct D. No. B
baichuan4 B. Yes, with p=3. B
doubao D. No.

The polynomial x^2 - 12 does not satisfy the Eisenstein criterion with any prime p.
B
minimax The Eisenstein criterion for irreducibility states that a polynomial \( f(x) = a_nx^n + a_{n-1}x^{n-1} + \ldots + a_1x + a_0 \) with integer coefficients is irreducible over the rationals if there exists a prime number \( p \) such that:

1. \( p \) divides all coefficients \( a_i \) for \( i < n \),
2. \( p \) does not divide \( a_n \),
3. \( p^2 \) does not divide \( a_0 \).

Let's apply this criterion to the polynomial \( f(x) = x^2 - 12 \):

1. \( p \) must divide both \( a_0 = -12 \) and \( a_1 = 0 \) (since there is no \( x \) term, we consider its coefficient to be 0).
2. \( p \) must not divide \( a_2 = 1 \) (the coefficient of \( x^2 \)).
3. \( p^2 \) must not divide \( a_0 = -12 \).

Looking at the options given:

A. If \( p = 2 \), then \( p \) divides \( a_0 \) but \( p^2 = 4 \) also divides \( a_0 \), so condition 3 fails.
B. If \( p = 3 \), then \( p \) divides \( a_0 \) but \( p^2 = 9 \) does not divide \( a_0 \), and \( p \) does not divide \( a_2 \), so conditions 1, 2, and 3 are satisfied.
C. If \( p = 5 \), then \( p \) does not divide \( a_0 \), so condition 1 fails.
D. If the polynomial is reducible, then it does not satisfy the Eisenstein criterion.

Therefore, the correct answer is:

B. Yes, with p=3.
B
kimi The Eisenstein criterion states that a polynomial \( f(x) \) with integer coefficients is irreducible over the rational numbers \( \mathbb{Q} \) if there exists a prime number \( p \) such that:

1. \( p \) divides the coefficient of every term of \( f(x) \) except the leading coefficient.
2. \( p^2 \) does not divide the leading coefficient.
3. \( p \) divides the constant term.

Let's apply this to the polynomial \( f(x) = x^2 - 12 \).

1. The coefficients are 1 and -12. The prime numbers that divide -12 are 2 and 3.
2. The leading coefficient is 1, so \( p^2 \) cannot divide it.
3. The constant term is -12.

Now let's check the options:

A. \( p = 2 \): \( 2 \) divides the coefficient of \( x \) (which is 0) and the constant term (-12), but \( 2^2 = 4 \) does not divide the leading coefficient (1). So, this does not satisfy the Eisenstein criterion.

B. \( p = 3 \): \( 3 \) divides the coefficient of \( x \) (which is 0) and the constant term (-12), and \( 3^2 = 9 \) does not divide the leading coefficient (1). This satisfies the Eisenstein criterion.

C. \( p = 5 \): \( 5 \) does not divide the coefficient of \( x \) (which is 0), so this does not satisfy the Eisenstein criterion.

D. No: This would be incorrect if there were a prime number that satisfies the Eisenstein criterion, which we have found in option B.

Answer: B. Yes, with p=3.
B
wenxinyiyan B

Explanation:
The Eisenstein criterion states that a polynomial \(f(x) = a_nx^n + a_{n-1}x^{n-1} + \cdots + a_0\) with integer coefficients is irreducible over \(\mathbb{Q}\) if there exists a prime number \(p\) such that:

1. \(p\) divides \(a_i\) for all \(i \neq n\),
2. \(p^2\) does not divide \(a_0\),
3. \(p\) does not divide \(a_n\).

For the polynomial \(x^2 - 12\), we have \(a_2 = 1\), \(a_1 = 0\), and \(a_0 = -12\). We need to find a prime \(p\) that satisfies the Eisenstein criterion.

* For \(p = 2\), condition 1 is satisfied since \(2\) divides \(a_1 = 0\) and \(a_0 = -12\). However, condition 2 is not satisfied because \(2^2 = 4\) divides \(a_0 = -12\).
* For \(p = 3\), condition 1 is satisfied since \(3\) divides \(a_1 = 0\) and \(a_0 = -12\). Condition 2 is satisfied because \(3^2 = 9\) does not divide \(a_0 = -12\). Condition 3 is also satisfied because \(3\) does not divide \(a_2 = 1\).
* For \(p = 5\), condition 1 is not satisfied because \(5\) does not divide \(a_0 = -12\).

Therefore, the polynomial \(x^2 - 12\) satisfies the Eisenstein criterion for irreducibility over \(\mathbb{Q}\) with \(p = 3\).
B
zhipu To determine whether the polynomial \( x^2 - 12 \) satisfies the Eisenstein criterion for irreducibility over \( \mathbb{Q} \), we need to check the conditions of the criterion for some prime \( p \).

The Eisenstein criterion states that a polynomial \( a_n x^n + a_{n-1} x^{n-1} + \cdots + a_1 x + a_0 \) with integer coefficients is irreducible over \( \mathbb{Q} \) if there exists a prime \( p \) such that:
1. \( p \) divides \( a_i \) for all \( i \neq n \),
2. \( p \) does not divide \( a_n \),
3. \( p^2 \) does not divide \( a_0 \).

For the polynomial \( x^2 - 12 \):
- \( a_2 = 1 \) (coefficient of \( x^2 \)),
- \( a_1 = 0 \) (coefficient of \( x \)),
- \( a_0 = -12 \) (constant term).

Let's check each option:

**Option A: \( p = 2 \)**
1. \( 2 \) divides \( a_1 = 0 \) and \( a_0 = -12 \).
2. \( 2 \) does not divide \( a_2 = 1 \).
3. \( 2^2 = 4 \) does not divide \( a_0 = -12 \).

All conditions are satisfied for \( p = 2 \).

**Option B: \( p = 3 \)**
1. \( 3 \) divides \( a_1 = 0 \), but \( 3 \) does not divide \( a_0 = -12 \) (since \( -12 \div 3 = -4 \), which is an integer, but we need \( p^2 \) not to divide \( a_0 \)).
2. \( 3 \) does not divide \( a_2 = 1 \).

The first condition fails for \( p = 3 \).

**Option C: \( p = 5 \)**
1. \( 5 \) divides \( a_1 = 0 \), but \( 5 \) does not divide \( a_0 = -12 \).
2. \( 5 \) does not divide \( a_2 = 1 \).

The first condition fails for \( p = 5 \).

**Option D: No**
Since we found that \( p = 2 \) satisfies the Eisenstein criterion, this option is incorrect.

Therefore, the correct answer is:
**A. Yes, with p=2.**
B
gpto1 B B
deepseekv3 To determine whether the polynomial \( x^2 - 12 \) in \( \mathbb{Z}[x] \) satisfies the Eisenstein criterion for irreducibility over \( \mathbb{Q} \), we need to check if there exists a prime number \( p \) such that:

1. \( p \) divides all the coefficients of the polynomial except the leading coefficient.
2. \( p \) does not divide the leading coefficient.
3. \( p^2 \) does not divide the constant term.

Let's analyze the polynomial \( x^2 - 12 \):

- The coefficients are \( 1 \) (leading coefficient) and \( -12 \) (constant term).

Now, let's check the options:

**Option A: \( p = 2 \)**
- \( 2 \) divides \( -12 \).
- \( 2 \) does not divide the leading coefficient \( 1 \).
- \( 2^2 = 4 \) divides \( -12 \).

Since \( 2^2 \) divides the constant term, the Eisenstein criterion is not satisfied with \( p = 2 \).

**Option B: \( p = 3 \)**
- \( 3 \) divides \( -12 \).
- \( 3 \) does not divide the leading coefficient \( 1 \).
- \( 3^2 = 9 \) does not divide \( -12 \).

The Eisenstein criterion is satisfied with \( p = 3 \).

**Option C: \( p = 5 \)**
- \( 5 \) does not divide \( -12 \).

The Eisenstein criterion is not satisfied with \( p = 5 \).

**Option D: No**
This option would be correct if there were no prime \( p \) satisfying the Eisenstein criterion. However, we found that \( p = 3 \) satisfies the criterion.

Therefore, the correct answer is:

**B. Yes, with \( p=3 \).**
B