Re: Gaussian Elimination wont work in my example

*To*: mathgroup at smc.vnet.net*Subject*: [mg13456] Re: Gaussian Elimination wont work in my example*From*: Tobias Oed <tobias at physics.odu.edu>*Date*: Fri, 24 Jul 1998 01:45:41 -0400*Organization*: Old Dominion University*References*: <6p6shi$5o2@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Cheng L L wrote: > > I have tried to solve a matrix > > {{-4, -2},{-2, -1}]. e =0 where e is a 1x2 matrix say [{a, b}] and > Tranpose[Conjugate[e]].e =1. I use Guassian Elimanation "LinearSolve" > to solve this equation, but it all the time gives out {0,0}, the answer > is not what I want in my case. Please help me to solve this puzzle. > Many thanks. > > Best regards, > LL Cheng > (City University of Hong Kong, EE Dept) > > email : eeacheng at cityu.edu.hk In[1]:= m={{-4, -2},{-2, -1}} Out[1]= {{-4, -2}, {-2, -1}} In[2]:= Det[m] Out[2]= 0 => You have none or an infinity of solutions In[3]:= e={{a},{b}} Out[3]= {{a}, {b}} In[4]:= Map[First[#]==0 &,m.e] Out[4]= {-4 a - 2 b == 0, -2 a - b == 0} In[5]:= Solve[%,a] //InputForm Out[5] //InputForm= {{a -> -b/2}} Tobias