Re: An unknown Greek matrix

*To*: mathgroup at smc.vnet.net*Subject*: [mg129982] Re: An unknown Greek matrix*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Sat, 2 Mar 2013 03:44:11 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20130301022642.797786882@smc.vnet.net>

A = {{5, 0}, {0, 10}}; B = {{6, 3}, {1, 12}}; L = {1, 1}; Lambda = {Subscript[lambda, 1], Subscript[lambda, 2]}; Solve[Lambda.B == Lambda.A + L, Lambda] {{Subscript[lambda, 1] -> -1, Subscript[lambda, 2] -> 2}} Bob Hanlon On Thu, Feb 28, 2013 at 9:26 PM, <marshfeldman at gmail.com> wrote: > Forgive me if this is obvious, but I'm a Mathematica newbie and have given up trying to figure this out any other way. > > I have the following defined matrices: > > A = {{5, 0}, {0, 10}} > B = {{6, 3}, {1, 12}} > > and a row vector: > > L = {{1, 1}}. > > I don't know how to use Greek here, so I'll use "Lambda" as the name of a row vector whose name is really the Greek letter lambda capitalized and "lambda" for as the name of the elements of Lambda subscripted, with the elements really being lower-case versions of the Greek letter lambda and subscripts indicated by appending _n, where n is the subscript (e.g. lambda_1 is lowercase lambda subscripted with 1). In other words, > > Lambda = {{lambda_1, lambda_2}}. > > Now given the following equation, solve for Lambda: > > Lambda B = Lambda A + L. > > Also, display the elements of Lambda as > > lambda_1 = -1 > lambda_2 = 2. > > Can one do this in Mathematica? How? >