solving unknowns in matrix - in Maxima



see http://www.math.utexas.edu/pipermail/maxima/2013/031378.html

 Evan Cooch <evan.cooch at gmail.com> writes:
   > Greetings --
   >
   > Consider the following matrix:
   >
   > a : matrix([-0.7-0.3*h1,0.6-0.6*h1],[0.5-0.5*h2,-0.35-0.65*h2]);
   >
   > I'm trying to solve for h1 and h2, such that dominant eigenvalue of a
is = 0.
   >
   > I know how to do this in a couple of other CAS systems, but am stumped
   > with Maxima. I know the solution in thiscase is
   >
   > h2=(11-81*h1)/(151-21*h1)
   >
   > Any pointers would be much appreciated (to aid and abet my attempt to
   > port a bunch of teaching material to Maxima).
   >
   > Thanks!

 My solution:
(%i1) a : matrix([-0.7-0.3*h1,0.6-0.6*h1],[0.5-0.5*h2,-0.35-0.65*h2])$
(%i2) determinant(a);
(%o2) (-0.3*h1-0.7)*(-0.65*h2-0.35)-(0.6-0.6*h1)*(0.5-0.5*h2)
(%i3) solve(%,h2);
(%o3) [h2=(81*h1-11)/(21*h1-151)]

Best

Aleksas D