disp('The discriminant of    a x**2 + b x +c is to be computed');
disp('to determine the root of the quadratic equation      ');
a=input(' give the value of a= ');
b=input(' give the value of b= ');
c=input(' give the value of c= ');

discr= b*b -4*a*c;
disp([' The discriminant is ' num2str(discr)]);
disp('If negative  : two distinc (and conjugate) complex numbers as roots');
disp('If 0         : duplicate root');
disp('If positive  : two distinct real roots');

