Re: Approximation

• To: mathgroup at smc.vnet.net
• Subject: [mg116561] Re: Approximation
• From: Rui <rui.rojo at gmail.com>
• Date: Sat, 19 Feb 2011 05:16:05 -0500 (EST)
• References: <ijgdb5\$bs1\$1@smc.vnet.net>

```On Feb 16, 6:44 am, Alexei Boulbitch <alexei.boulbi... at iee.lu> wrote:
> 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.
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> 11, rue Edmond Reuter
> L-5326 CONTERN
> Luxembourg
>
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>
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>
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>
> --
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