Re: Problems Using Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg117262] Re: Problems Using Mathematica
- From: David Bailey <dave at removedbailey.co.uk>
- Date: Sun, 13 Mar 2011 05:26:20 -0500 (EST)
- References: <ilfi6t$79c$1@smc.vnet.net>
On 12/03/2011 10:34, Crystal wrote: > Hello Friends, > I'm almost racking my head against the wall trying to solve this > problem... maybe because I'm new to Mathematica but there's no point > trying to learn without help from forums like this. > > Here are my problems (I'm hoping the questions should render well in > Mathematica environment with copy/paste): > > Problem 1 > > \[Bullet] Consider the following set of equations > > {A E^(\[Alpha] Subscript[L, 1]) - C Cos[\[Gamma] Subscript[L, 1]] - > B Sin[\[Gamma] Subscript[L, 1]] == 0, > A E^(\[Alpha] Subscript[L, 1]) \[Alpha] - > B \[Gamma] Cos[\[Gamma] Subscript[L, 1]] + > C \[Gamma] Sin[\[Gamma] Subscript[L, 1]] == > 0, -D E^(-\[Alpha] Subscript[L, 2]) + C Cos[\[Gamma] Subscript[L, > 2]] + > B Sin[\[Gamma] Subscript[L, 2]] == 0, > D E^(-\[Alpha] Subscript[L, 2]) \[Alpha] + > B \[Gamma] Cos[\[Gamma] Subscript[L, 2]] - > C \[Gamma] Sin[\[Gamma] Subscript[L, 2]] == 0} > > where > > \[Alpha]^2 + \[Gamma]^2 == v^2 > > with given v and > > L == -Subscript[L, 1] + Subscript[L, 2] > > Derive the eigenvalue equation in terms of \[Gamma] and L with v as > the parameter. > > > > > Problem 2 > > \[Bullet] Given the reflection amplitude given by > > B[z] == -((I E^(-(1/2) I z \[CapitalDelta]\[Beta]) A[0] Sinh[s (L - > z)] > \!\(\*SuperscriptBox["\[Kappa]", "*"]\))/( > s Cosh[L s] + 1/2 I (I g + \[CapitalDelta]\[Beta]) Sinh[L s])) > > where > > s == Sqrt[-(1/ > 4) (I g + \[CapitalDelta]\[Beta])^2 + \[LeftBracketingBar]\[Kappa] > \ > \[RightBracketingBar]^2] > > the reflection gain is given by > > Subscript[G, refl] == \[LeftBracketingBar]B[0]/A[0]\ > [RightBracketingBar]^2 > > For simplicity, put \[Kappa]=1,L=1 and find the lowest three numerical > solutions of \[CapitalDelta]\[Beta] and g for infinite gain. > > Thanks so much > That looks awfully like exercises that someone has set for you to solve! If there is something specific you don't understand about Mathematica, why not ask that! David Bailey http://www.dbaileyconsultancy.co.uk