<![CDATA[Math Is Fun Forum / open interval and tangent line... need help with proof]]>2010-04-17T06:44:32ZFluxBBhttp://www.mathisfunforum.com/viewtopic.php?id=13926<![CDATA[Re: open interval and tangent line... need help with proof]]>lawilson8510 wrote:

Suppose that I is ...

shouldn't it be "Suppose that I am ..."??

]]>http://www.mathisfunforum.com/profile.php?id=127002010-04-17T06:44:32Zhttp://www.mathisfunforum.com/viewtopic.php?pid=134380#p134380<![CDATA[open interval and tangent line... need help with proof]]>Suppose that I is an open interval and that f "(x) is greater than or equal to 0 for all x in I. If b is in I, then show that the part of the graph of f on I is never below the tangent line to the graph at (b, f(b)).