Re: Approximation

*To*: mathgroup at smc.vnet.net*Subject*: [mg116479] Re: Approximation*From*: Alexei Boulbitch <alexei.boulbitch at iee.lu>*Date*: Wed, 16 Feb 2011 06:44:41 -0500 (EST)

The operators Series[]//Normal will do the job for you. For example: expr = 1/Sqrt[R^2 + G^2]; Simplify[Series[expr, {R, 0, 2}], Assumptions -> G> 0] Simplify[Series[expr, {R, 0, 2}] // Normal, Assumptions -> G> 0] SeriesData[R, 0, {G^(-1), 0, Rational[-1, 2] G^(-3)}, 0, 3, 1] 1/G - R^2/(2 G^3) Have fun. Alexei Is there a way to tell Mathematica to simplify and approximate an expression assuming things such as "R is a lot smaller than G"/ R<<G ? If not so, how would you approach the problem? Thanks -- Alexei Boulbitch, Dr. habil. Senior Scientist Material Development IEE S.A. ZAE Weiergewan 11, rue Edmond Reuter L-5326 CONTERN Luxembourg Tel: +352 2454 2566 Fax: +352 2454 3566 Mobile: +49 (0) 151 52 40 66 44 e-mail: alexei.boulbitch at iee.lu 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.