Cute Log Series Bug
- To: mathgroup at yoda.physics.unc.edu (Mathematica User's Group)
- Subject: Cute Log Series Bug
- From: Keith Clay <clay at galileo.phys.washington.edu>
- Date: Fri, 23 Jul 93 10:08:06 MDT
I have no idea what is happening here, but I thought I should send a copy
of this output. Evidently there is a bug in Series or Log:
In[1]:= Series[ Log[x(1+x)], {x,0,1} ]
2
Out[1]= Log[x] + O[x] <- WRONG!
In[2]:= Series[ Log[x(1+x)], {x,0,2} ]
2
x 3
Out[2]= Log[x] + x - -- + O[x] <- Yes. Notice the
2 Order(x) part.
In[3]:= Series[ PowerExpand[Log[x(1+x)]], {x,0,1}]
2
Out[3]= Log[x] + x + O[x] <- PowerExpand works, too.
Any explanations? Strange, in any case.
Keith
clay at galileo.phys.washington.edu