// This function solves finds the roots of an equation in
// n dimensions.  
 
function [r]=quad_solve (x1, start, ends, increment, w1, w2, P)

   r = quad_disc ([x1;start], w1, w2, P);
   vsign = sign (r);
   rold = r;

   for x2=start:increment:ends,
      r = quad_disc ([x1;x2], w1, w2, P);
      if sign (r) ~= vsign then
         r=[x2-increment rold; x2 r];
         break;
      end;
      rold = r;
   end;