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Groups > comp.soft-sys.math.mathematica > #1714
| From | Peter Pein <petsie@dordos.net> |
|---|---|
| Newsgroups | comp.soft-sys.math.mathematica |
| Subject | Re: Trignometric rules |
| Date | 2011-04-16 11:34 +0000 |
| Organization | Steven M. Christensen and Associates, Inc and MathTensor, Inc. |
| Message-ID | <iobut1$bci$1@smc.vnet.net> (permalink) |
| References | <io6d3h$drj$1@smc.vnet.net> <io8tn0$qam$1@smc.vnet.net> |
Am 15.04.2011 09:56, schrieb Peter Pein: > Am 14.04.2011 11:00, schrieb Chelly: >> I have an expression as hsown below >> >> tt = -4 k1^2 v^2 \[Epsilon]1^2 \[Epsilon]c^2 Cos[2 d1 + d2 + d3] - >> 2 k1 k2 u^2 \[Epsilon]1 Cos[d1 + d2 - \[Phi]b - \[Phi]r] + >> 2 k1^2 v^2 \[Epsilon]1^2 \[Epsilon]c^2 Cos[ >> 2 d1 + d2 + d3 - \[Phi]b - \[Phi]r] + >> 2 k1^3 k2 v^2 \[Epsilon]1^3 \[Epsilon]c^2 Cos[ >> d1 + d3 + \[Phi]b + \[Phi]r] + >> 2 k1^2 u^2 \[Epsilon]1^2 Cos[2 d1 + d2 + d3 + \[Phi]b + \[Phi]r] - >> 2 k1^2 v^2 \[Epsilon]1^2 \[Epsilon]c^2 Cos[ >> 2 d1 + d2 + d3 + \[Phi]b + \[Phi]r]; >> >> I'd like to replace any term containing Cos[+/- phib + x_] with 2 Sin [+/-phib] Sin[x]. How do I go about doing it. >> >> Thanks >> Chelly >> > > Hi Chelly, > > use pattern matching: > > tt /. Cos[pb:(s_. \[Phi]b /; Abs[s] == 1) + x_.] :> 2 Sin[pb] Sin[x] > > Peter > Oops! Of course: tt /. Cos[pb:(s_. \[Phi]b /; Abs[s] == 1) + x_.] :> 2 Sin[s pb] Sin[x] sorry, Peter
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Trignometric rules Chelly <chelly85086@gmail.com> - 2011-04-14 09:00 +0000
Re: Trignometric rules Peter Pein <petsie@dordos.net> - 2011-04-15 07:56 +0000
Re: Trignometric rules Peter Pein <petsie@dordos.net> - 2011-04-16 11:34 +0000
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