Re: Exclude O[] from Series[] for Solve[] in Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg92845] Re: Exclude O[] from Series[] for Solve[] in Mathematica*From*: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>*Date*: Wed, 15 Oct 2008 05:36:03 -0400 (EDT)

I expand a function as a Series[] but the O[] part prevents Solve[] from working. I try Part[] and it returns something which also confuses Solve[]. First[] works, but produces useless results, but this is why I am sure this is what I want to do. Hi, Vasos, There is a function Normal[] that does the job. Compare: In[5]:= Series[Sin[x], {x, 0, 5}] Out[5]= (SeriesData[$CellContext`x, 0, { 1, 0, Rational[-1, 6], 0, Rational[1, 120]}, 1, 6, 1]) with the following: In[4]:= Normal[Series[Sin[x], {x, 0, 5}]] Out[4]= x - x^3/6 + x^5/120 Check Help/Series for more details. With this the Solve operator works: In[7]:= Solve[Normal[Series[Sin[x], {x, 0, 5}]] == 0, x] Out[7]= {{x -> 0}, {x -> -Sqrt[2 (5 - \[ImaginaryI] Sqrt[5])]}, {x -> Sqrt[2 (5 - \[ImaginaryI] Sqrt[5])]}, {x -> -Sqrt[ 2 (5 + \[ImaginaryI] Sqrt[5])]}, {x -> Sqrt[ 2 (5 + \[ImaginaryI] Sqrt[5])]}} Have success, Alexei -- Alexei Boulbitch, Dr., Habil. Senior Scientist IEE S.A. ZAE Weiergewan 11, rue Edmond Reuter L-5326 Contern Luxembourg Phone: +352 2454 2566 Fax: +352 2454 3566 Website: www.iee.lu This e-mail may contain trade secrets or privileged, undisclosed or otherwise confidential information. If you are not the intended recipient and have received this e-mail in error, you are hereby notified that any review, copying or distribution of it is strictly prohibited. Please inform us immediately and destroy the original transmittal from your system. Thank you for your co-operation.