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<pre>
<pre>
{{Proof|title=Proof that <math>\sqrt{2}</math> is irrational|
{{Proof
contents=Assume <math>\sqrt{2}</math> is ''p''/''q'', where ''p'', ''q'' ∈ ℤ<sub>>0</sub> and gcd(''p'', ''q'') = 1. Then ''p''<sup>2</sup>/''q''<sup>2</sup> = 2, and ''p''<sup>2</sup> = 2''q''<sup>2</sup>. Since ''p''<sup>2</sup> is even, and gcd(''p'', ''q'') = 1, gcd(''p''<sup>2</sup>, ''q''<sup>2</sup>) = 1, ''q''<sup>2</sup> must be odd. Hence ''p''<sup>2</sup> ≡ 2 (mod 4), which is impossible because the square of an integer must always be congruent to 0 or 1 (mod 4).  
| title=Proof that the root of any integer is either an integer or irrational
| contents=Assume <math>\sqrt[n]{m}</math> is {{nowrap|''p'' / ''q''}}, where {{nowrap|''p'', ''q'' ∈ ℤ<sup>+</sup>}} and {{nowrap|gcd(''p'', ''q'') {{=}} 1}}. Then  
{{nowrap|''p''<sup>n</sup> / ''q''<sup>n</sup> {{=}} ''m''}}, and {{nowrap|''p''<sup>n</sup> {{=}} m''q''<sup>n</sup>}}. This means ''p'' is divisible by ''m''. Therefore, there exists some integer ''r'' such that {{nowrap|p {{=}} mr}}, so we now have {{nowrap|''m''<sup>n</sup>''r''<sup>n</sup> {{=}} m''q''<sup>n</sup>}}. Dividing both sides by ''m'' gives{{nowrap|''m''<sup>{{nowrap|n &minus; 1}}</sup>''r''<sup>n</sup> {{=}} ''q''<sup>n</sup>}}. This means that ''q'' must also be divisible by ''m'', which is a contradiction, since ''p'' and ''q'' were assumed to be relatively prime. {{qed}}
}}
}}
</pre>
</pre>
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{{Databox
{{Databox
| 1=Proof that <math>\sqrt{2}</math> is irrational
| 1=Proof that the root of any integer is either an integer or irrational
| 2=Assume <math>\sqrt{2}</math> is ''p''/''q'', where ''p'', ''q'' ∈ ℤ<sub>>0</sub> and gcd(''p'', ''q'') = 1. Then ''p''<sup>2</sup>/''q''<sup>2</sup> = 2, and ''p''<sup>2</sup> = 2''q''<sup>2</sup>. Since ''p''<sup>2</sup> is even, and gcd(''p'', ''q'') = 1, gcd(''p''<sup>2</sup>, ''q''<sup>2</sup>) = 1, ''q''<sup>2</sup> must be odd. Hence ''p''<sup>2</sup> ≡ 2 (mod 4), which is impossible because the square of an integer must always be congruent to 0 or 1 (mod 4). {{qed}}
| 2=Assume <math>\sqrt[n]{m}</math> is {{nowrap|''p'' / ''q''}}, where {{nowrap|''p'', ''q'' ∈ ℤ<sup>+</sup>}} and {{nowrap|gcd(''p'', ''q'') {{=}} 1}}. Then  
{{nowrap|''p<sup>n</sup>'' / ''q<sup>n</sup>'' {{=}} ''m''}}, and {{nowrap|''p<sup>n</sup>'' {{=}} m''q<sup>n</sup>''}}. This means ''p'' is divisible by ''m''. Therefore, there exists some integer ''r'' such that {{nowrap|''p'' {{=}} ''mr''}}, so we now have {{nowrap|''m<sup>n</sup>r<sup>n</sup>'' {{=}} ''mq<sup>n</sup>''}}. Dividing both sides by ''m'' gives {{nowrap|''m<sup>n&nbsp;&minus;&nbsp;1</sup>r<sup>n</sup>'' {{=}} ''q<sup>n</sup>''}}. This means that ''q'' must also be divisible by ''m'', which is a contradiction, since ''p'' and ''q'' were assumed to be relatively prime. {{qed}}
}}
}}


Note: To include the character <code>|</code>, it must be escaped as <code>{{((}}!{{))}}</code>, unless it appears inside preformatted text (such as a <nowiki><syntaxhighlight></nowiki> or <nowiki><math></nowiki> tag).
Note: To include the pipe (<code>|</code>) character, it must be escaped as <code>{{((}}!{{))}}</code>, unless it appears inside preformatted text (such as a <nowiki><syntaxhighlight></nowiki> or <nowiki><math></nowiki> tag). Additionally, to include the equals sign, it must be escaped as <code>{{((}}={{))}}</code>.


=== See also ===
=== See also ===
* [[Template:Theorem]]
* [[Template:Theorem]]

Revision as of 18:47, 9 July 2024

Usage

You type:

{{Proof
| title=Proof that the root of any integer is either an integer or irrational
| contents=Assume <math>\sqrt[n]{m}</math> is {{nowrap|''p'' / ''q''}}, where {{nowrap|''p'', ''q'' ∈ ℤ<sup>+</sup>}} and {{nowrap|gcd(''p'', ''q'') {{=}} 1}}. Then 
{{nowrap|''p''<sup>n</sup> / ''q''<sup>n</sup> {{=}} ''m''}}, and {{nowrap|''p''<sup>n</sup> {{=}} m''q''<sup>n</sup>}}. This means ''p'' is divisible by ''m''. Therefore, there exists some integer ''r'' such that {{nowrap|p {{=}} mr}}, so we now have {{nowrap|''m''<sup>n</sup>''r''<sup>n</sup> {{=}} m''q''<sup>n</sup>}}. Dividing both sides by ''m'' gives{{nowrap|''m''<sup>{{nowrap|n − 1}}</sup>''r''<sup>n</sup> {{=}} ''q''<sup>n</sup>}}. This means that ''q'' must also be divisible by ''m'', which is a contradiction, since ''p'' and ''q'' were assumed to be relatively prime. {{qed}}
}}

You get:

Proof that the root of any integer is either an integer or irrational
Assume [math]\displaystyle{ \sqrt[n]{m} }[/math] is p / q, where p, q ∈ ℤ+ and gcd(p, q) = 1. Then pn / qn = m, and pn = mqn. This means p is divisible by m. Therefore, there exists some integer r such that p = mr, so we now have mnrn = mqn. Dividing both sides by m gives mn − 1rn = qn. This means that q must also be divisible by m, which is a contradiction, since p and q were assumed to be relatively prime. [math]\displaystyle{ \square }[/math]

Note: To include the pipe (|) character, it must be escaped as {{!}}, unless it appears inside preformatted text (such as a <syntaxhighlight> or <math> tag). Additionally, to include the equals sign, it must be escaped as {{=}}.

See also