natural logarithm expressed as integral of 1/x
<ul><li><a href="//commons.wikimedia.org/wiki/File:Log-pole-x.svg" title="File:Log-pole-x.svg">Log-pole-x.svg</a>: <a href="//commons.wikimedia.org/wiki/User:Wojciech_mula" title="User:Wojciech mula">Wojciech Muła</a></li>
<li>derivative work: <a href="//commons.wikimedia.org/wiki/User:Jakob.scholbach" title="User:Jakob.scholbach">Jakob.scholbach</a> (<a href="//commons.wikimedia.org/wiki/User_talk:Jakob.scholbach" title="User talk:Jakob.scholbach"><span class="signature-talk">talk</span></a>)</li></ul>
<ul><li><a href="//commons.wikimedia.org/wiki/File:Log-pole-x.svg" title="File:Log-pole-x.svg">Log-pole-x.svg</a></li></ul>