function [root1,root2,ier]=quadroots0(a,b,c)
    if a==0
      if b==0
	ier='no roots a=b=0';
      else
	root1=-c/b;
	root2=root1;
	ier='one roots a=0';
      end;
    else
      disc= b*b-4*a*c;
      if disc < 0
	im=sqrt(-disc)/(2*a);
	re=-b/(2*a);
	root1=re+i*im;
	root2=re-i*im;
      else
	diff=sqrt(disc)/(2*a);
	same=-b/(2*a);
	root1=same+diff;
	root2=same-diff;
      end;
    end;