简单测试了一下deepseek的初等数学能力
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#1 简单测试了一下deepseek的初等数学能力
比如这个简单题目 x^2 + x + 1 = 0 ( mod 11) 的整数解是啥?deepseek转了半天,说server busy,please try later。
又改成问这个题目的解有几个(因为无解,所以等于是提示DS了)? 转了半天,还是server busy,please try later。
是真的用的人太多了?
前面问了它一个级数收敛的问题,它立即就答了,答得不错。
按说这个初等数论题也最多是同样难度的,看来LLM还是这个样子,没刷过的题,就不会做。
又改成问这个题目的解有几个(因为无解,所以等于是提示DS了)? 转了半天,还是server busy,please try later。
是真的用的人太多了?
前面问了它一个级数收敛的问题,它立即就答了,答得不错。
按说这个初等数论题也最多是同样难度的,看来LLM还是这个样子,没刷过的题,就不会做。
菜畦同志,1973年参加工作,1975年加入终国共惨党,现任政治局常委、中央办公厅主任。
#3 Re: 简单测试了一下deepseek的初等数学能力
但是问他个简单级数收敛题,它就立即给出答案。看来主要还是靠刷题。
菜畦同志,1973年参加工作,1975年加入终国共惨党,现任政治局常委、中央办公厅主任。
#6 Re: 简单测试了一下deepseek的初等数学能力
可能是用的人太多,问了一个问题两次,一次能答,一次只是不停地转, 然后server busy。
菜畦同志,1973年参加工作,1975年加入终国共惨党,现任政治局常委、中央办公厅主任。
#7 Re: 简单测试了一下deepseek的初等数学能力
完了,现在拒绝回答了,问啥都是server busy
菜畦同志,1973年参加工作,1975年加入终国共惨党,现任政治局常委、中央办公厅主任。
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#8 Re: 简单测试了一下deepseek的初等数学能力
我觉得这个deepseak是不是靠数据造假出来结果的?非常值得怀疑Veggiebed 写了: 2025年 1月 28日 14:20 比如这个简单题目 x^2 + x + 1 = 0 ( mod 11) 的整数解是啥?deepseek转了半天,说server busy,please try later。
又改成问这个题目的解有几个(因为无解,所以等于是提示DS了)? 转了半天,还是server busy,please try later。
是真的用的人太多了?
前面问了它一个级数收敛的问题,它立即就答了,答得不错。
按说这个初等数论题也最多是同样难度的,看来LLM还是这个样子,没刷过的题,就不会做。
#11 Re: 简单测试了一下deepseek的初等数学能力
这回又能用了,有时会做错,比如这个明显答案的问题:x^2 = 10 (mod 30), 居然用了Chinese remainder theorem后说无解。
菜畦同志,1973年参加工作,1975年加入终国共惨党,现任政治局常委、中央办公厅主任。
#12 Re: 简单测试了一下deepseek的初等数学能力
半个小时我的本地deepseek-r1:32b 终于出完结果嘞
>>> integer solution of x^2 + x + 1 = 0 ( mod 11)
<think>
Alright, so I need to find all integer solutions for the equation \(x^2 + x + 1 = 0 \mod{11}\). Hmm, okay. Let me
think about how to approach this.
First off, solving quadratic equations modulo a prime number like 11 can sometimes be done by trying out all
possible residues from 0 up to 10 and seeing which ones satisfy the equation. Since 11 is not too large, that
might be manageable. But before jumping into that, maybe there's a smarter way.
I remember something about quadratic equations modulo primes. There's this thing called the discriminant. For a
general quadratic equation \(ax^2 + bx + c = 0\), the discriminant is \(D = b^2 - 4ac\). If the discriminant is a
square modulo the prime, then there are solutions; otherwise, there aren't.
So in this case, let's compute the discriminant. Here, \(a = 1\), \(b = 1\), and \(c = 1\), so:
\(D = (1)^2 - 4(1)(1) = 1 - 4 = -3\).
Hmm, okay, so we have a discriminant of \(-3\) modulo 11. I need to check if \(-3\) is a quadratic residue modulo
11. In other words, does there exist some number \(y\) such that \(y^2 \equiv -3 \mod{11}\)?
Let me compute \(-3\) mod 11 first. Since 11 - 3 = 8, so \(-3 \equiv 8 \mod{11}\). So I need to check if 8 is a
quadratic residue modulo 11.
To do that, one method is to use Euler's criterion, which says that for an odd prime \(p\), and integer \(a\) not
divisible by \(p\), \(a^{(p-1)/2} \equiv 1 \mod{p}\) if \(a\) is a quadratic residue, and \(-1\) otherwise.
So let me compute \(8^{5} \mod{11}\). Why 5? Because (11 - 1)/2 = 5. Let's calculate:
\(8^1 = 8\)
\(8^2 = 64\), which is 64 - 5*11=64-55=9 mod 11.
\(8^3 = 8 * 9 = 72\). 72 divided by 11: 6*11=66, so 72-66=6. So \(8^3 \equiv 6 \mod{11}\).
\(8^4 = 8 * 6 = 48\), which is 48 - 4*11=48-44=4 mod 11.
\(8^5 = 8 * 4 = 32\). 32 - 2*11=32-22=10 mod 11. So \(8^5 \equiv 10 \mod{11}\).
Since 10 is not congruent to 1, Euler's criterion tells me that 8 is not a quadratic residue modulo 11. Therefore,
the discriminant isn't a square in this field, which suggests that there are no solutions.
Wait, but let me double-check because sometimes even if I think I'm correct, it's better to be thorough. Maybe
trying all possible residues from 0 to 10 will confirm whether any satisfy the equation \(x^2 + x + 1 \equiv 0
\mod{11}\).
Alright, let me create a table of values for each x in [0, 10] and compute \(x^2 + x + 1\) mod 11.
Starting with x=0:
\(0^2 + 0 + 1 = 1\). 1 mod 11 is 1. Not zero.
x=1:
\(1 + 1 + 1 = 3\). 3 mod 11 is 3. Nope.
x=2:
4 + 2 + 1 =7. 7 mod 11 is 7. Still not.
x=3:
9 + 3 + 1=13. 13-11=2. Not zero.
x=4:
16 + 4 + 1=21. 21 - 2*11=21-22=-1≡10 mod11. Still not zero.
x=5:
25 +5 +1=31. 31 -2*11=9. Not zero.
x=6:
36 +6 +1=43. 43 - 3*11=43-33=10. Not zero.
x=7:
49 +7 +1=57. 57 - 5*11=57-55=2. Nope.
x=8:
64 +8 +1=73. 73 -6*11=73-66=7. Not zero.
x=9:
81 +9 +1=91. 91 -8*11=91-88=3. Nope.
x=10:
100 +10 +1=111. 111 -10*11=111-110=1. Not zero.
Hmm, so none of the residues from 0 to 10 satisfy the equation \(x^2 + x + 1 \equiv 0 \mod{11}\). So that confirms
it: there are no solutions modulo 11 for this quadratic equation.
Wait a second, but I just remembered something. Quadratic equations over finite fields can have 0, 1, or 2
solutions. Since the discriminant wasn't a square, we have zero solutions here, which matches with our exhaustive
check above.
Alternatively, maybe there's another method involving completing the square? Let me try that for practice.
Starting with \(x^2 + x + 1 \equiv 0 \mod{11}\).
Completing the square:
\(x^2 + x = -1 \mod{11}\)
Take half of the coefficient of x, which is 1/2. Since we're working mod11, 1/2 is equivalent to 6 because
2*6=12≡1 mod11.
So, \( (x + 6)^2 - 36 ≡ -1 \mod{11}\).
Wait, let me compute that step by step:
\(x^2 + x = (x + 1/2)^2 - (1/2)^2\). So,
\( (x + 6)^2 - 36 ≡ -1 \mod{11} \)
Compute \( -36 mod11 \): 36 /11 is 3*11=33, so 36-33=3. Thus, -36≡-3≡8 mod11.
So:
\( (x + 6)^2 ≡ -1 + 36 mod11\), which simplifies to \( (x + 6)^2 ≡ (-1) + (36 mod11) \).
Wait, hold on. Let me redo that step because I might have messed up.
We had:
\( x^2 + x = -1 \mod{11} \)
Complete the square:
\( x^2 + x + (1/4) = -1 + (1/4) \mod{11} \)
So,
\( (x + 1/2)^2 ≡ (-1) + (1/4) mod11 \)
Compute \(1/4\) modulo11: since 4*3=12≡1 mod11, so 1/4≡3 mod11.
Thus:
Left side: \( (x + 6)^2 \mod{11} \) because 1/2 is 6 in mod11.
Right side: (-1) + 3 ≡ 2 mod11.
So the equation becomes:
\( (x + 6)^2 ≡ 2 mod11 \)
Now, so we need to solve \( y^2 ≡ 2 mod11 \), where y = x +6. So does 2 have square roots modulo11?
Let me check which squares give 2 mod11.
Compute squares of numbers from 0 to 10:
0²=0
1²=1
2²=4
3²=9
4²=16≡5
5²=25≡3
6²=36≡3
7²=49≡5
8²=64≡9
9²=81≡4
10²=100≡1.
So the squares modulo11 are 0,1,3,4,5,9. So 2 isn't a square modulo11 either. Therefore, equation \( y^2 ≡2
\mod{11}\) has no solution, so original equation also has no solutions.
Wait, but earlier when computing Euler's criterion for discriminant 8 (from the first method), we saw that 8 was
not a quadratic residue as well? Or wait, in the second method, we arrived at needing to solve y²≡2. So yeah, same
result: no solution.
So all methods converge on there being no solutions to this equation in integers mod11.
Therefore, I think it's settled. There are no integer solutions modulo11 for \( x^2 +x +1 ≡0 \mod{11} \).
**Final Answer**
There are no integer solutions. The final answer is \boxed{\text{No solution}}.
</think>
To determine the integer solutions of the quadratic equation \(x^2 + x + 1 \equiv 0 \pmod{11}\), we can use
several methods:
1. **Exhaustive Check**:
- We check all residues from 0 to 10 modulo 11.
- None of these values satisfy the equation \(x^2 + x + 1 \equiv 0 \pmod{11}\).
2. **Quadratic Residue Check**:
- The discriminant of the quadratic equation is calculated as \(\Delta = b^2 - 4ac = 1 - 4 = -3\).
- Converting \(-3\) modulo 11, we get \(8\). We check if 8 is a quadratic residue modulo 11.
- The squares modulo 11 are calculated: 0, 1, 3, 4, 5, 9. Since 8 is not among these, it is not a quadratic
residue.
3. **Completing the Square**:
- Rewrite the equation as \(x^2 + x = -1 \pmod{11}\).
- Complete the square: \((x + 6)^2 - 36 \equiv -1 \pmod{11}\).
- Simplifying, we get \((x + 6)^2 \equiv 2 \pmod{11}\). Checking if 2 is a quadratic residue modulo 11, we find
it is not.
Since all methods confirm that there are no solutions, we conclude:
\[
\boxed{\text{No solution}}
\]
>>> integer solution of x^2 + x + 1 = 0 ( mod 11)
<think>
Alright, so I need to find all integer solutions for the equation \(x^2 + x + 1 = 0 \mod{11}\). Hmm, okay. Let me
think about how to approach this.
First off, solving quadratic equations modulo a prime number like 11 can sometimes be done by trying out all
possible residues from 0 up to 10 and seeing which ones satisfy the equation. Since 11 is not too large, that
might be manageable. But before jumping into that, maybe there's a smarter way.
I remember something about quadratic equations modulo primes. There's this thing called the discriminant. For a
general quadratic equation \(ax^2 + bx + c = 0\), the discriminant is \(D = b^2 - 4ac\). If the discriminant is a
square modulo the prime, then there are solutions; otherwise, there aren't.
So in this case, let's compute the discriminant. Here, \(a = 1\), \(b = 1\), and \(c = 1\), so:
\(D = (1)^2 - 4(1)(1) = 1 - 4 = -3\).
Hmm, okay, so we have a discriminant of \(-3\) modulo 11. I need to check if \(-3\) is a quadratic residue modulo
11. In other words, does there exist some number \(y\) such that \(y^2 \equiv -3 \mod{11}\)?
Let me compute \(-3\) mod 11 first. Since 11 - 3 = 8, so \(-3 \equiv 8 \mod{11}\). So I need to check if 8 is a
quadratic residue modulo 11.
To do that, one method is to use Euler's criterion, which says that for an odd prime \(p\), and integer \(a\) not
divisible by \(p\), \(a^{(p-1)/2} \equiv 1 \mod{p}\) if \(a\) is a quadratic residue, and \(-1\) otherwise.
So let me compute \(8^{5} \mod{11}\). Why 5? Because (11 - 1)/2 = 5. Let's calculate:
\(8^1 = 8\)
\(8^2 = 64\), which is 64 - 5*11=64-55=9 mod 11.
\(8^3 = 8 * 9 = 72\). 72 divided by 11: 6*11=66, so 72-66=6. So \(8^3 \equiv 6 \mod{11}\).
\(8^4 = 8 * 6 = 48\), which is 48 - 4*11=48-44=4 mod 11.
\(8^5 = 8 * 4 = 32\). 32 - 2*11=32-22=10 mod 11. So \(8^5 \equiv 10 \mod{11}\).
Since 10 is not congruent to 1, Euler's criterion tells me that 8 is not a quadratic residue modulo 11. Therefore,
the discriminant isn't a square in this field, which suggests that there are no solutions.
Wait, but let me double-check because sometimes even if I think I'm correct, it's better to be thorough. Maybe
trying all possible residues from 0 to 10 will confirm whether any satisfy the equation \(x^2 + x + 1 \equiv 0
\mod{11}\).
Alright, let me create a table of values for each x in [0, 10] and compute \(x^2 + x + 1\) mod 11.
Starting with x=0:
\(0^2 + 0 + 1 = 1\). 1 mod 11 is 1. Not zero.
x=1:
\(1 + 1 + 1 = 3\). 3 mod 11 is 3. Nope.
x=2:
4 + 2 + 1 =7. 7 mod 11 is 7. Still not.
x=3:
9 + 3 + 1=13. 13-11=2. Not zero.
x=4:
16 + 4 + 1=21. 21 - 2*11=21-22=-1≡10 mod11. Still not zero.
x=5:
25 +5 +1=31. 31 -2*11=9. Not zero.
x=6:
36 +6 +1=43. 43 - 3*11=43-33=10. Not zero.
x=7:
49 +7 +1=57. 57 - 5*11=57-55=2. Nope.
x=8:
64 +8 +1=73. 73 -6*11=73-66=7. Not zero.
x=9:
81 +9 +1=91. 91 -8*11=91-88=3. Nope.
x=10:
100 +10 +1=111. 111 -10*11=111-110=1. Not zero.
Hmm, so none of the residues from 0 to 10 satisfy the equation \(x^2 + x + 1 \equiv 0 \mod{11}\). So that confirms
it: there are no solutions modulo 11 for this quadratic equation.
Wait a second, but I just remembered something. Quadratic equations over finite fields can have 0, 1, or 2
solutions. Since the discriminant wasn't a square, we have zero solutions here, which matches with our exhaustive
check above.
Alternatively, maybe there's another method involving completing the square? Let me try that for practice.
Starting with \(x^2 + x + 1 \equiv 0 \mod{11}\).
Completing the square:
\(x^2 + x = -1 \mod{11}\)
Take half of the coefficient of x, which is 1/2. Since we're working mod11, 1/2 is equivalent to 6 because
2*6=12≡1 mod11.
So, \( (x + 6)^2 - 36 ≡ -1 \mod{11}\).
Wait, let me compute that step by step:
\(x^2 + x = (x + 1/2)^2 - (1/2)^2\). So,
\( (x + 6)^2 - 36 ≡ -1 \mod{11} \)
Compute \( -36 mod11 \): 36 /11 is 3*11=33, so 36-33=3. Thus, -36≡-3≡8 mod11.
So:
\( (x + 6)^2 ≡ -1 + 36 mod11\), which simplifies to \( (x + 6)^2 ≡ (-1) + (36 mod11) \).
Wait, hold on. Let me redo that step because I might have messed up.
We had:
\( x^2 + x = -1 \mod{11} \)
Complete the square:
\( x^2 + x + (1/4) = -1 + (1/4) \mod{11} \)
So,
\( (x + 1/2)^2 ≡ (-1) + (1/4) mod11 \)
Compute \(1/4\) modulo11: since 4*3=12≡1 mod11, so 1/4≡3 mod11.
Thus:
Left side: \( (x + 6)^2 \mod{11} \) because 1/2 is 6 in mod11.
Right side: (-1) + 3 ≡ 2 mod11.
So the equation becomes:
\( (x + 6)^2 ≡ 2 mod11 \)
Now, so we need to solve \( y^2 ≡ 2 mod11 \), where y = x +6. So does 2 have square roots modulo11?
Let me check which squares give 2 mod11.
Compute squares of numbers from 0 to 10:
0²=0
1²=1
2²=4
3²=9
4²=16≡5
5²=25≡3
6²=36≡3
7²=49≡5
8²=64≡9
9²=81≡4
10²=100≡1.
So the squares modulo11 are 0,1,3,4,5,9. So 2 isn't a square modulo11 either. Therefore, equation \( y^2 ≡2
\mod{11}\) has no solution, so original equation also has no solutions.
Wait, but earlier when computing Euler's criterion for discriminant 8 (from the first method), we saw that 8 was
not a quadratic residue as well? Or wait, in the second method, we arrived at needing to solve y²≡2. So yeah, same
result: no solution.
So all methods converge on there being no solutions to this equation in integers mod11.
Therefore, I think it's settled. There are no integer solutions modulo11 for \( x^2 +x +1 ≡0 \mod{11} \).
**Final Answer**
There are no integer solutions. The final answer is \boxed{\text{No solution}}.
</think>
To determine the integer solutions of the quadratic equation \(x^2 + x + 1 \equiv 0 \pmod{11}\), we can use
several methods:
1. **Exhaustive Check**:
- We check all residues from 0 to 10 modulo 11.
- None of these values satisfy the equation \(x^2 + x + 1 \equiv 0 \pmod{11}\).
2. **Quadratic Residue Check**:
- The discriminant of the quadratic equation is calculated as \(\Delta = b^2 - 4ac = 1 - 4 = -3\).
- Converting \(-3\) modulo 11, we get \(8\). We check if 8 is a quadratic residue modulo 11.
- The squares modulo 11 are calculated: 0, 1, 3, 4, 5, 9. Since 8 is not among these, it is not a quadratic
residue.
3. **Completing the Square**:
- Rewrite the equation as \(x^2 + x = -1 \pmod{11}\).
- Complete the square: \((x + 6)^2 - 36 \equiv -1 \pmod{11}\).
- Simplifying, we get \((x + 6)^2 \equiv 2 \pmod{11}\). Checking if 2 is a quadratic residue modulo 11, we find
it is not.
Since all methods confirm that there are no solutions, we conclude:
\[
\boxed{\text{No solution}}
\]
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#14 Re: 简单测试了一下deepseek的初等数学能力
我发现不开deep search比较蠢。昨天看网上有人黑 说不知道3.11 和3.9 哪个大。我立刻试了一下果然如此 而且重复问每次回答不一样 有的时候说3.11 大给出一大堆推理过程,说 所以 结论是 3.9 大…
推理过程说的也离谱 说3.11 等于 3.10
打开deep search 以后几次还可以
推理过程说的也离谱 说3.11 等于 3.10
打开deep search 以后几次还可以
#15 Re: 简单测试了一下deepseek的初等数学能力
不开deepthink就没意义了,就好比普通chatgpt和o1的差别,天差地别闪光的二猫 写了: 2025年 1月 28日 16:53 我发现不开deep search比较蠢。昨天看网上有人黑 说不知道3.11 和3.9 哪个大。我立刻试了一下果然如此 而且重复问每次回答不一样 有的时候说3.11 大给出一大堆推理过程,说 所以 结论是 3.9 大…
推理过程说的也离谱 说3.11 等于 3.10
打开deep search 以后几次还可以
#16 Re: 简单测试了一下deepseek的初等数学能力
我的本地版deepseek-r1:8b 为什么5秒就出结果了(ヅ) 写了: 2025年 1月 28日 16:15 半个小时我的本地deepseek-r1:32b 终于出完结果嘞
>>> integer solution of x^2 + x + 1 = 0 ( mod 11)
<think>
Alright, so I need to find all integer solutions for the equation \(x^2 + x + 1 = 0 \mod{11}\). Hmm, okay. Let me
think about how to approach this.
First off, solving quadratic equations modulo a prime number like 11 can sometimes be done by trying out all
possible residues from 0 up to 10 and seeing which ones satisfy the equation. Since 11 is not too large, that
might be manageable. But before jumping into that, maybe there's a smarter way.
I remember something about quadratic equations modulo primes. There's this thing called the discriminant. For a
general quadratic equation \(ax^2 + bx + c = 0\), the discriminant is \(D = b^2 - 4ac\). If the discriminant is a
square modulo the prime, then there are solutions; otherwise, there aren't.
So in this case, let's compute the discriminant. Here, \(a = 1\), \(b = 1\), and \(c = 1\), so:
\(D = (1)^2 - 4(1)(1) = 1 - 4 = -3\).
Hmm, okay, so we have a discriminant of \(-3\) modulo 11. I need to check if \(-3\) is a quadratic residue modulo
11. In other words, does there exist some number \(y\) such that \(y^2 \equiv -3 \mod{11}\)?
Let me compute \(-3\) mod 11 first. Since 11 - 3 = 8, so \(-3 \equiv 8 \mod{11}\). So I need to check if 8 is a
quadratic residue modulo 11.
To do that, one method is to use Euler's criterion, which says that for an odd prime \(p\), and integer \(a\) not
divisible by \(p\), \(a^{(p-1)/2} \equiv 1 \mod{p}\) if \(a\) is a quadratic residue, and \(-1\) otherwise.
So let me compute \(8^{5} \mod{11}\). Why 5? Because (11 - 1)/2 = 5. Let's calculate:
\(8^1 = 8\)
\(8^2 = 64\), which is 64 - 5*11=64-55=9 mod 11.
\(8^3 = 8 * 9 = 72\). 72 divided by 11: 6*11=66, so 72-66=6. So \(8^3 \equiv 6 \mod{11}\).
\(8^4 = 8 * 6 = 48\), which is 48 - 4*11=48-44=4 mod 11.
\(8^5 = 8 * 4 = 32\). 32 - 2*11=32-22=10 mod 11. So \(8^5 \equiv 10 \mod{11}\).
Since 10 is not congruent to 1, Euler's criterion tells me that 8 is not a quadratic residue modulo 11. Therefore,
the discriminant isn't a square in this field, which suggests that there are no solutions.
Wait, but let me double-check because sometimes even if I think I'm correct, it's better to be thorough. Maybe
trying all possible residues from 0 to 10 will confirm whether any satisfy the equation \(x^2 + x + 1 \equiv 0
\mod{11}\).
Alright, let me create a table of values for each x in [0, 10] and compute \(x^2 + x + 1\) mod 11.
Starting with x=0:
\(0^2 + 0 + 1 = 1\). 1 mod 11 is 1. Not zero.
x=1:
\(1 + 1 + 1 = 3\). 3 mod 11 is 3. Nope.
x=2:
4 + 2 + 1 =7. 7 mod 11 is 7. Still not.
x=3:
9 + 3 + 1=13. 13-11=2. Not zero.
x=4:
16 + 4 + 1=21. 21 - 2*11=21-22=-1≡10 mod11. Still not zero.
x=5:
25 +5 +1=31. 31 -2*11=9. Not zero.
x=6:
36 +6 +1=43. 43 - 3*11=43-33=10. Not zero.
x=7:
49 +7 +1=57. 57 - 5*11=57-55=2. Nope.
x=8:
64 +8 +1=73. 73 -6*11=73-66=7. Not zero.
x=9:
81 +9 +1=91. 91 -8*11=91-88=3. Nope.
x=10:
100 +10 +1=111. 111 -10*11=111-110=1. Not zero.
Hmm, so none of the residues from 0 to 10 satisfy the equation \(x^2 + x + 1 \equiv 0 \mod{11}\). So that confirms
it: there are no solutions modulo 11 for this quadratic equation.
Wait a second, but I just remembered something. Quadratic equations over finite fields can have 0, 1, or 2
solutions. Since the discriminant wasn't a square, we have zero solutions here, which matches with our exhaustive
check above.
Alternatively, maybe there's another method involving completing the square? Let me try that for practice.
Starting with \(x^2 + x + 1 \equiv 0 \mod{11}\).
Completing the square:
\(x^2 + x = -1 \mod{11}\)
Take half of the coefficient of x, which is 1/2. Since we're working mod11, 1/2 is equivalent to 6 because
2*6=12≡1 mod11.
So, \( (x + 6)^2 - 36 ≡ -1 \mod{11}\).
Wait, let me compute that step by step:
\(x^2 + x = (x + 1/2)^2 - (1/2)^2\). So,
\( (x + 6)^2 - 36 ≡ -1 \mod{11} \)
Compute \( -36 mod11 \): 36 /11 is 3*11=33, so 36-33=3. Thus, -36≡-3≡8 mod11.
So:
\( (x + 6)^2 ≡ -1 + 36 mod11\), which simplifies to \( (x + 6)^2 ≡ (-1) + (36 mod11) \).
Wait, hold on. Let me redo that step because I might have messed up.
We had:
\( x^2 + x = -1 \mod{11} \)
Complete the square:
\( x^2 + x + (1/4) = -1 + (1/4) \mod{11} \)
So,
\( (x + 1/2)^2 ≡ (-1) + (1/4) mod11 \)
Compute \(1/4\) modulo11: since 4*3=12≡1 mod11, so 1/4≡3 mod11.
Thus:
Left side: \( (x + 6)^2 \mod{11} \) because 1/2 is 6 in mod11.
Right side: (-1) + 3 ≡ 2 mod11.
So the equation becomes:
\( (x + 6)^2 ≡ 2 mod11 \)
Now, so we need to solve \( y^2 ≡ 2 mod11 \), where y = x +6. So does 2 have square roots modulo11?
Let me check which squares give 2 mod11.
Compute squares of numbers from 0 to 10:
0²=0
1²=1
2²=4
3²=9
4²=16≡5
5²=25≡3
6²=36≡3
7²=49≡5
8²=64≡9
9²=81≡4
10²=100≡1.
So the squares modulo11 are 0,1,3,4,5,9. So 2 isn't a square modulo11 either. Therefore, equation \( y^2 ≡2
\mod{11}\) has no solution, so original equation also has no solutions.
Wait, but earlier when computing Euler's criterion for discriminant 8 (from the first method), we saw that 8 was
not a quadratic residue as well? Or wait, in the second method, we arrived at needing to solve y²≡2. So yeah, same
result: no solution.
So all methods converge on there being no solutions to this equation in integers mod11.
Therefore, I think it's settled. There are no integer solutions modulo11 for \( x^2 +x +1 ≡0 \mod{11} \).
**Final Answer**
There are no integer solutions. The final answer is \boxed{\text{No solution}}.
</think>
To determine the integer solutions of the quadratic equation \(x^2 + x + 1 \equiv 0 \pmod{11}\), we can use
several methods:
1. **Exhaustive Check**:
- We check all residues from 0 to 10 modulo 11.
- None of these values satisfy the equation \(x^2 + x + 1 \equiv 0 \pmod{11}\).
2. **Quadratic Residue Check**:
- The discriminant of the quadratic equation is calculated as \(\Delta = b^2 - 4ac = 1 - 4 = -3\).
- Converting \(-3\) modulo 11, we get \(8\). We check if 8 is a quadratic residue modulo 11.
- The squares modulo 11 are calculated: 0, 1, 3, 4, 5, 9. Since 8 is not among these, it is not a quadratic
residue.
3. **Completing the Square**:
- Rewrite the equation as \(x^2 + x = -1 \pmod{11}\).
- Complete the square: \((x + 6)^2 - 36 \equiv -1 \pmod{11}\).
- Simplifying, we get \((x + 6)^2 \equiv 2 \pmod{11}\). Checking if 2 is a quadratic residue modulo 11, we find
it is not.
Since all methods confirm that there are no solutions, we conclude:
\[
\boxed{\text{No solution}}
\]
>>> x^2 + x + 1 = 0 ( mod 11) 的整数解是啥
<think>
好,我现在遇到了一个同余方程的问题,需要解决它。题目是:x² + x + 1 ≡ 0 (mod 11),我要找出满足这个方程的整数解。
首先,我回忆一下,模运算中的解法通常涉及到逐一测试可能的值,或者使用一些代数技巧来简化问题。这里,模数是11,所以x的
取值范围应该在0到10之间,因为模11下,余数只能是从0到10。
接下来,我想到可以将方程改写成一个更易处理的形式,可能会帮助我找到解。原方程是x² + x + 1 ≡ 0 (mod 11),也就是x²
+ x ≡ -1 (mod 11)。因为-1在模11下等价于10,所以我可以写成x² + x ≡ 10 (mod 11)。
然后,我想到将这个方程转化为标准的二次方程形式,可能会有助于求解。标准形式是ax² + bx + c ≡ d (mod m),这里a=1,
b=1,c=1,d=10,m=11。
接下来,我想到可以使用求根公式来解决模运算中的二次方程问题。在普通情况下,求根公式是x = [-b ± √(b² - 4ac)] /
(2a)。在这里,代入数值得到:
x = [-1 ± √(1 - 4*1*1)] / (2*1)
x = [-1 ± √(-3)] / 2
但是,这里出现了一个问题,因为-3在模11下不是一个完全平方数。我需要找到在模11下,哪些数的平方等于-3(即8)。于是,我
开始列出0到10之间所有数的平方,看看哪个等于8:
0² ≡ 0 (mod 11)
1² ≡ 1
2² ≡ 4
3² ≡ 9
4² ≡ 16 ≡ 5 (因为16 - 11 = 5)
5² ≡ 25 ≡ 3 (25 - 22 = 3)
6² ≡ 36 ≡ 3 (36 - 33 = 3)
7² ≡ 49 ≡ 5 (49 - 44 = 5)
8² ≡ 64 ≡ 9 (64 - 55 = 9)
9² ≡ 81 ≡ 4 (81 - 77 = 4)
10² ≡ 100 ≡ 1 (100 - 99 = 1)
看来在模11下,没有数的平方等于8。那么,原方程是否有解呢?这似乎没有解,但我不太确定。
为了验证这一点,我可以尝试逐一测试x从0到10,看看哪些值满足x² + x + 1 ≡ 0 (mod 11)。
让我列出所有可能的x值和对应的x² + x + 1:
- x = 0: 0 + 0 + 1 = 1 ≡ 1 ≠ 0
- x = 1: 1 + 1 + 1 = 3 ≡ 3 ≠ 0
- x = 2: 4 + 2 + 1 = 7 ≡ 7 ≠ 0
- x = 3: 9 + 3 + 1 = 13 ≡ 2 ≠ 0
- x = 4: 16 + 4 + 1 = 21 ≡ 10 ≠ 0
- x = 5: 25 + 5 + 1 = 31 ≡ 9 ≠ 0
- x = 6: 36 + 6 + 1 = 43 ≡ 10 ≠ 0
- x = 7: 49 + 7 + 1 = 57 ≡ 2 ≠ 0
- x = 8: 64 + 8 + 1 = 73 ≡ 73 - 66 = 7 ≠ 0
- x = 9: 81 + 9 + 1 = 91 ≡ 91 - 88 = 3 ≠ 0
- x = 10: 100 + 10 + 1 = 111 ≡ 111 - 110 = 1 ≠ 0
看来,所有x从0到10都没有满足方程的值,这意味着在模11下,这个方程没有解。
但是,我有点怀疑自己是否正确,因为有时候可能会漏掉某些情况或者计算错误。我再仔细检查一下每一个步骤。
首先,在转换方程时,确实得到了x² + x ≡ 10 (mod 11)。然后,使用求根公式得到√(-3),但在模11下,-3等价于8,我需要找
到数y,使得y² ≡ 8 (mod 11)。
然而,从之前的计算可以看出,没有这样的y存在,因为0到10之间的平方数分别是0,1,4,9,5,3,3,5,9,4,1。因此,确实没有数满足
y² ≡ 8 (mod 11),这意味着原方程在模11下没有解。
另外,我已经逐一测试了所有可能的x值,都没有满足x² + x + 1 ≡ 0 (mod 11)。因此,可以确认这个方程在模11下没有整数解。
</think>
根据上述思考过程,我们可以得出以下结论:
**步骤解析:**
1. **问题理解:**
我们需要解同余方程 \( x^2 + x + 1 \equiv 0 \pmod{11} \),即找到满足该方程的整数 \( x \) 在模11下的值。
2. **代数变形:**
将原方程改写为:
\[
x^2 + x \equiv -1 \pmod{11}
\]
由于 \(-1 \equiv 10 \pmod{11}\),方程变为:
\[
x^2 + x \equiv 10 \pmod{11}
\]
3. **求根公式应用:**
使用二次方程求解公式,得到:
\[
x = \frac{-1 \pm \sqrt{1 - 4 \cdot 1 \cdot 1}}{2} = \frac{-1 \pm \sqrt{-3}}{2}
\]
在模11下,\(-3 \equiv 8\),所以需要找到满足 \( y^2 \equiv 8 \pmod{11} \) 的整数 \( y \)。
4. **平方剩余分析:**
计算模11下的平方值:
\[
0^2 = 0, \quad 1^2=1,\ 2^2=4,\ 3^2=9,\ 4^2=5,\ 5^2=3,\ 6^2=3,\ 7^2=5,\ 8^2=9,\ 9^2=4,\ 10^2=1
\]
发现没有数的平方等于8,即 \( 8 \) 不是模11下的平方剩余。
5. **验证解的存在性:**
因为没有满足 \( y^2 \equiv 8 \pmod{11} \) 的整数,因此原方程在模11下无解。
6. **逐一测试验证:**
逐个代入 \( x = 0,1,2,\ldots,10 \),计算结果均不满足 \( x^2 + x + 1 \equiv 0 \pmod{11} \)。
**最终结论:**
在模11下,同余方程 \( x^2 + x + 1 \equiv 0 \pmod{11} \) 没有整数解。
#17 Re: 简单测试了一下deepseek的初等数学能力
本地部署,怎么搞?需要什么level的硬件?这几天deepseek基本用不了,问就是server busyMaja101 写了: 2025年 1月 29日 00:20 我的本地版deepseek-r1:8b 为什么5秒就出结果了
>>> x^2 + x + 1 = 0 ( mod 11) 的整数解是啥
<think>
好,我现在遇到了一个同余方程的问题,需要解决它。题目是:x² + x + 1 ≡ 0 (mod 11),我要找出满足这个方程的整数解。
首先,我回忆一下,模运算中的解法通常涉及到逐一测试可能的值,或者使用一些代数技巧来简化问题。这里,模数是11,所以x的
取值范围应该在0到10之间,因为模11下,余数只能是从0到10。
接下来,我想到可以将方程改写成一个更易处理的形式,可能会帮助我找到解。原方程是x² + x + 1 ≡ 0 (mod 11),也就是x²
+ x ≡ -1 (mod 11)。因为-1在模11下等价于10,所以我可以写成x² + x ≡ 10 (mod 11)。
然后,我想到将这个方程转化为标准的二次方程形式,可能会有助于求解。标准形式是ax² + bx + c ≡ d (mod m),这里a=1,
b=1,c=1,d=10,m=11。
接下来,我想到可以使用求根公式来解决模运算中的二次方程问题。在普通情况下,求根公式是x = [-b ± √(b² - 4ac)] /
(2a)。在这里,代入数值得到:
x = [-1 ± √(1 - 4*1*1)] / (2*1)
x = [-1 ± √(-3)] / 2
但是,这里出现了一个问题,因为-3在模11下不是一个完全平方数。我需要找到在模11下,哪些数的平方等于-3(即8)。于是,我
开始列出0到10之间所有数的平方,看看哪个等于8:
0² ≡ 0 (mod 11)
1² ≡ 1
2² ≡ 4
3² ≡ 9
4² ≡ 16 ≡ 5 (因为16 - 11 = 5)
5² ≡ 25 ≡ 3 (25 - 22 = 3)
6² ≡ 36 ≡ 3 (36 - 33 = 3)
7² ≡ 49 ≡ 5 (49 - 44 = 5)
8² ≡ 64 ≡ 9 (64 - 55 = 9)
9² ≡ 81 ≡ 4 (81 - 77 = 4)
10² ≡ 100 ≡ 1 (100 - 99 = 1)
看来在模11下,没有数的平方等于8。那么,原方程是否有解呢?这似乎没有解,但我不太确定。
为了验证这一点,我可以尝试逐一测试x从0到10,看看哪些值满足x² + x + 1 ≡ 0 (mod 11)。
让我列出所有可能的x值和对应的x² + x + 1:
- x = 0: 0 + 0 + 1 = 1 ≡ 1 ≠ 0
- x = 1: 1 + 1 + 1 = 3 ≡ 3 ≠ 0
- x = 2: 4 + 2 + 1 = 7 ≡ 7 ≠ 0
- x = 3: 9 + 3 + 1 = 13 ≡ 2 ≠ 0
- x = 4: 16 + 4 + 1 = 21 ≡ 10 ≠ 0
- x = 5: 25 + 5 + 1 = 31 ≡ 9 ≠ 0
- x = 6: 36 + 6 + 1 = 43 ≡ 10 ≠ 0
- x = 7: 49 + 7 + 1 = 57 ≡ 2 ≠ 0
- x = 8: 64 + 8 + 1 = 73 ≡ 73 - 66 = 7 ≠ 0
- x = 9: 81 + 9 + 1 = 91 ≡ 91 - 88 = 3 ≠ 0
- x = 10: 100 + 10 + 1 = 111 ≡ 111 - 110 = 1 ≠ 0
看来,所有x从0到10都没有满足方程的值,这意味着在模11下,这个方程没有解。
但是,我有点怀疑自己是否正确,因为有时候可能会漏掉某些情况或者计算错误。我再仔细检查一下每一个步骤。
首先,在转换方程时,确实得到了x² + x ≡ 10 (mod 11)。然后,使用求根公式得到√(-3),但在模11下,-3等价于8,我需要找
到数y,使得y² ≡ 8 (mod 11)。
然而,从之前的计算可以看出,没有这样的y存在,因为0到10之间的平方数分别是0,1,4,9,5,3,3,5,9,4,1。因此,确实没有数满足
y² ≡ 8 (mod 11),这意味着原方程在模11下没有解。
另外,我已经逐一测试了所有可能的x值,都没有满足x² + x + 1 ≡ 0 (mod 11)。因此,可以确认这个方程在模11下没有整数解。
</think>
根据上述思考过程,我们可以得出以下结论:
**步骤解析:**
1. **问题理解:**
我们需要解同余方程 \( x^2 + x + 1 \equiv 0 \pmod{11} \),即找到满足该方程的整数 \( x \) 在模11下的值。
2. **代数变形:**
将原方程改写为:
\[
x^2 + x \equiv -1 \pmod{11}
\]
由于 \(-1 \equiv 10 \pmod{11}\),方程变为:
\[
x^2 + x \equiv 10 \pmod{11}
\]
3. **求根公式应用:**
使用二次方程求解公式,得到:
\[
x = \frac{-1 \pm \sqrt{1 - 4 \cdot 1 \cdot 1}}{2} = \frac{-1 \pm \sqrt{-3}}{2}
\]
在模11下,\(-3 \equiv 8\),所以需要找到满足 \( y^2 \equiv 8 \pmod{11} \) 的整数 \( y \)。
4. **平方剩余分析:**
计算模11下的平方值:
\[
0^2 = 0, \quad 1^2=1,\ 2^2=4,\ 3^2=9,\ 4^2=5,\ 5^2=3,\ 6^2=3,\ 7^2=5,\ 8^2=9,\ 9^2=4,\ 10^2=1
\]
发现没有数的平方等于8,即 \( 8 \) 不是模11下的平方剩余。
5. **验证解的存在性:**
因为没有满足 \( y^2 \equiv 8 \pmod{11} \) 的整数,因此原方程在模11下无解。
6. **逐一测试验证:**
逐个代入 \( x = 0,1,2,\ldots,10 \),计算结果均不满足 \( x^2 + x + 1 \equiv 0 \pmod{11} \)。
**最终结论:**
在模11下,同余方程 \( x^2 + x + 1 \equiv 0 \pmod{11} \) 没有整数解。
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#19 Re: 简单测试了一下deepseek的初等数学能力
我本地安装了最大的版本(70b),给出的答案是:
### Final Answer
The solutions are \(\boxed{4}\) and \(\boxed{8}\) modulo 11.
### Final Answer
The solutions are \(\boxed{4}\) and \(\boxed{8}\) modulo 11.
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- 论坛支柱
2024年度优秀版主
TheMatrix 的博客 - 帖子互动: 279
- 帖子: 13694
- 注册时间: 2022年 7月 26日 00:35