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