code: private double computeB( Point2D_F64 x ) {
  		GeometryMath_F64.mult(A,x,Ax);
  
  		GeometryMath_F64.cross(x,Ax,t0);
  		GeometryMath_F64.cross(x,e2,t1);
  
  		double top = GeometryMath_F64.dot(t0,t1);
  		double bottom = t1.normSq();
  
  		return top/bottom;
  	}
docs: b = [(x cross (A*x))^T ( x cross e2 )] / || x cross e2 ||^2