14-240/Tutorial-Sep30: Difference between revisions

From Drorbn
Jump to navigationJump to search
Line 12: Line 12:
Solution:
Solution:


Let <math>a \in S</math> be the additive identity and <math>b \in S</math> be the multiplicative identity where <math>a \neq b</math>. After trial and error, we have the following addition and multiplication tables:
Let <math>S = \{ a, b \} </math> where <math>a</math> is the additive identity and <math>b</math> is the multiplicative identity and <math>a \neq b</math>. After trial and error, we have the following addition and multiplication tables:


{| class="wikitable"
{| class="wikitable"
Line 43: Line 43:
| <math>b</math>
| <math>b</math>
|}
|}

We verify that


==Nikita==
==Nikita==

Revision as of 21:11, 4 October 2014

Boris

Problem

Find a set [math]\displaystyle{ S }[/math] of two elements that satisfies the following:

  • [math]\displaystyle{ S }[/math] satisfies all the properties of the field except distributivity.
  • [math]\displaystyle{ \exists x \in S, 0x \neq 0 }[/math].

Solution:

Let [math]\displaystyle{ S = \{ a, b \} }[/math] where [math]\displaystyle{ a }[/math] is the additive identity and [math]\displaystyle{ b }[/math] is the multiplicative identity and [math]\displaystyle{ a \neq b }[/math]. After trial and error, we have the following addition and multiplication tables:

[math]\displaystyle{ + }[/math] [math]\displaystyle{ a }[/math] [math]\displaystyle{ b }[/math]
[math]\displaystyle{ a }[/math] [math]\displaystyle{ a }[/math] [math]\displaystyle{ b }[/math]
[math]\displaystyle{ b }[/math] [math]\displaystyle{ b }[/math] [math]\displaystyle{ a }[/math]
[math]\displaystyle{ \times }[/math] [math]\displaystyle{ b }[/math] [math]\displaystyle{ a }[/math]
[math]\displaystyle{ b }[/math] [math]\displaystyle{ b }[/math] [math]\displaystyle{ a }[/math]
[math]\displaystyle{ a }[/math] [math]\displaystyle{ a }[/math] [math]\displaystyle{ b }[/math]

We verify that

Nikita