Oops, that's what comes from working online... Having p²+pq+q²=13 allows p=1 and q=3 (or viceversa), producing roots 1, 3, and -4; p=-1 and q=-3 produces -1, -3, and 4 as roots.
blackjack
<a href="http://c.casalemedia.com/c?s=51816&f=3&id=0" target="_blank"><img src="http://as.casalemedia.com/s?s=51816&u=http://perplexus.info&f=3&id=0&if=0" width="120" height="600" border="0"></a>
flooble's webmaster puzzle
re(2): Some thoughts
