Why does x^0 equal 1?

Since basic school we know, that [math]x^0=1[/math], but only recently when our kids began to study mathematics we asked ourselves “why?”.

I came up with this explanation:

[math]x^0=x^{n-n}=x^n \times x^{-n}=\frac {x^n} {x^n}=1[/math]

Also a good test for the Easy LaTeX WordPress plug-in.

And here’s jsxgraph plug-in test:
Continue reading Why does x^0 equal 1?

External searching in mybb

Sometimes you need to integrate web-pages with corresponding forum threads. Here’s one of the way to do it.

$keywords=”MyBB integration”; // The search keywords
<!– The path to mybb search.php –>

<form method=”post” action=”http://www.yoursite.com/mybb/search.php”>
<input type=”hidden” name=”action” value=”do_search” />
<input type=”hidden” name=”keywords” value=”<?php echo $keywords; ?>” />
<!– search titles only –>
<input type=”hidden”  name=”postthread” value=”2″ />
<!– Search in all forums –>
<input type=”hidden” name=”forums[]” size=”15″ multiple=”multiple” value=”all”>
<!– All dates –>
<input type=”hidden” name=”postdate” value=”0″>
<input type=”hidden” name=”pddir” value=”1″ />
<input type=”hidden” name=”sortby” value=”lastpost”>
<input type=”hidden” name=”sortordr” value=”asc” />
<!– the result will be threads, not posts –>
<input type=”hidden” name=”showresults” value=”threads” />
<input type=”submit” class=”button” name=”submit” value=”Forum” />