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Dwarf
Posts:
22
Registered:
12/7/04


Solve results
Posted:
Oct 25, 1996 10:18 PM


I recently came upon this and was wondering if it's a Solve bug, some notation I'm not familiar with, or just an unfortunate happenstance.
When I give Mathematica the equation x^38==0, this is what it returns:
In[1]:= Solve[x^38==0,x] Out[1]= {{x > 2}, {x > 2*(1)^(1/3)}, {x > 2*(1)^(2/3)}}
But if I first factor the polynomial instead:
In[2]:= Solve[Factor[x^38]==0,x] Out[2]= {{x > 2}, {x > (2  2*I*3^(1/2))/2},{x > (2 + 2*I*3^(1/2))/2}}
if I use reduce instead of solve
In[3]:= Reduce[x^38==0,x] Out[3]= x == 2  x == (2  2*I*3^(1/2))/2  x == (2 + 2*I*3^(1/2))/2
My question is: why the different behaviors, and how can I tell in advance which to use?
++   I understand mine's a risky plan,  Greg Anderson  and your system can't miss  dwarf@wam.umd.edu  but is security, after all a cause  timbwolf@eng.umd.edu  or symptom of happiness.   ++ Dream Theater  A Matter of Time



