updated docs

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403913

docs/docs/optimization.xml

@@ -323,6 +323,7 @@
    subject to the following constraints:
       sum(alpha) == C 
       min(alpha) >= 0 
+   Where f is convex.  This means that Q should be positive-semidefinite.
 </pre>
 
          </description>