Re: Out[1]=((5-Sqrt[5])/20 + (5+Sqrt[5])/20 ) == 1/2 ???
- To: mathgroup at smc.vnet.net
- Subject: [mg20007] Re: Out[1]=((5-Sqrt[5])/20 + (5+Sqrt[5])/20 ) == 1/2 ???
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Sat, 25 Sep 1999 02:40:38 -0400
- Organization: Universitaet Leipzig
- References: <7se6fk$qsc@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
H Patrick, you ask is ( (5-Sqrt[5])/20 + (5+Sqrt[5])/20 ) equal to 1/2. This should be True. To evaluate this Mathematica don't call Together[]. It find that NumericQ[( (5-Sqrt[5])/20 + (5+Sqrt[5])/20 ) ] yield True and try to evaluate it numerical :-( This gives the message from the numerical evaluation. Hope that helps Jens Patrick McLean wrote: > > Can any one explain this behaviour??? > > > In[1]:= ( (5-Sqrt[5])/20 + (5+Sqrt[5])/20 ) == 1/2 > > $MaxExtraPrecision::meprec: > $MaxExtraPrecision = 50. reached while evaluating > 1 5 - Sqrt[5] 5 + Sqrt[5] > -(-) + ----------- + -----------. Increasing the value of > 2 20 20 > $MaxExtraPrecision may help resolve the uncertainty. > > 5 - Sqrt[5] 5 + Sqrt[5] 1 > Out[1]= ----------- + ----------- == - > 20 20 2 > Patrick McLean > > No news is good news...