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    <title>MaplePrimes - comments on Post, A compendium of inequalities -- how can it be used?</title>
    <link>http://www.mapleprimes.com/posts/40565-A-Compendium-Of-Inequalities--How</link>
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    <pubDate>Sat, 13 Jun 2026 23:37:40 GMT</pubDate>
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    <description>The latest comments added to the Post, A compendium of inequalities -- how can it be used?</description>
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      <title>MaplePrimes - comments on Post, A compendium of inequalities -- how can it be used?</title>
      <link>http://www.mapleprimes.com/posts/40565-A-Compendium-Of-Inequalities--How</link>
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    <item>
      <title>Inequalities</title>
      <link>http://www.mapleprimes.com/posts/40565-A-Compendium-Of-Inequalities--How?ref=Feed:MaplePrimes:A compendium of inequalities -- how can it be used?:Comments#comment74921</link>
      <itunes:summary>I wonder how many of these inequalities are true.  For example, I randomly chose Theorem 21 which says if x &gt; 0,

&lt;maple&gt;x/(x + floor(x)) + x/(x+frac(x)) &amp;gt;= 5/2&lt;/maple&gt;

This is wrong: the left side actually varies between 4/3 and 3/2.  Moreover, Maple can be persuaded to assert this:

&lt;pre&gt;
&gt; _EnvTry := hard:
  x := a + b:
  Q:= x/(x+b) + x/(x+a):
  is(Q &gt; 3/2) assuming a &gt;= 0, b &gt; 0;
&lt;/pre&gt;
&lt;maple&gt;false&lt;/maple&gt;

Note that the expression is symmetric in a and b; you can take a = frac(x) and b = floor(x) or vice versa, and at least one of these is strictly positive.

I doubt that a table of inequalities would be very useful in itself, because the one you want will hardly ever be in the table (though it might be a consequence of one or more items there).  I think this should be seen in the context of the need to improve Maple's ability to decide whether nonlinear inequalities are true in connection with the "assume" facilities.  For example:

&lt;pre&gt;
&gt; is(a^2 + b + 1 &gt;= a) assuming a &gt;= 0, b &gt;= 0;
&lt;maple&gt;FAIL&lt;/maple&gt;</itunes:summary>
      <description>The latest comments added to the Post, A compendium of inequalities -- how can it be used?</description>
      <guid>74921</guid>
      <pubDate>Wed, 07 Nov 2007 00:29:27 Z</pubDate>
      <itunes:author>Robert Israel</itunes:author>
      <author>Robert Israel</author>
    </item>
    <item>
      <title>Maple as help for a correct guess</title>
      <link>http://www.mapleprimes.com/posts/40565-A-Compendium-Of-Inequalities--How?ref=Feed:MaplePrimes:A compendium of inequalities -- how can it be used?:Comments#comment74919</link>
      <itunes:summary>but in the cited example Maple can be of help to guess the correct statement:

x/(x + floor(x)) + x/(x+frac(x)) -5/2;  plot(%,x=0 ..6);

or (the transformed one)

x/(x+b) + x/(x+a)-3/2; subs(a=frac(x),b=floor(x),%); plot(%,x=-3 ..16);</itunes:summary>
      <description>The latest comments added to the Post, A compendium of inequalities -- how can it be used?</description>
      <guid>74919</guid>
      <pubDate>Wed, 07 Nov 2007 01:58:12 Z</pubDate>
      <itunes:author>Axel Vogt</itunes:author>
      <author>Axel Vogt</author>
    </item>
    <item>
      <title>unimpressive results</title>
      <link>http://www.mapleprimes.com/posts/40565-A-Compendium-Of-Inequalities--How?ref=Feed:MaplePrimes:A compendium of inequalities -- how can it be used?:Comments#comment84705</link>
      <itunes:summary>The theorems seem mostly worthless.  Besides the error previously mentioned, the few I checked are overly conservative.  Consider theorem 1:
&lt;pre&gt;
floor(x)/(3*x+frac(x)) + frac(x)/(3*x+floor(x)) &amp;ge; 4/15
&lt;/pre&gt;
The real limit should be 2/7, not 4/15. Similarly for theorem 6, the right side should be 4/3/x, not the conservative 1/x.

Theorem 32 part 2 fails: 
&lt;pre&gt;
solve(y2 := abs(cos(floor(x))) + abs(cos(frac(x))) - abs(cos(x));
fsolve(y2, x=2.9..3);
                                2.966118521
limit(y2, x=3, left);
                           -cos(2) + cos(1) + cos(3)
evalf(%);
                                 -0.0335433542
&lt;/pre&gt;

So does Theorem 25, at multiple locations for x &amp;lt; 0:
&lt;pre&gt;
y := abs(sin(floor(x))) + abs(sin(frac(x))) + abs(cos(x)):
plot([1,y], x=-10..4);
limit(y, x=-2, left);evalf(%);
                                sin(3) - cos(2)

                                 0.5572668446
&lt;/pre&gt;
</itunes:summary>
      <description>The latest comments added to the Post, A compendium of inequalities -- how can it be used?</description>
      <guid>84705</guid>
      <pubDate>Mon, 12 Nov 2007 11:14:53 Z</pubDate>
      <itunes:author>Joe
 Riel
</itunes:author>
      <author>Joe
 Riel
</author>
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