function main()
    [root1, root2] = quadratic(1, sqrt(2), 1);
    disp(root1);
    disp(root2);
end

function [x1, x2] = quadratic(a, b, c)
% [x1, x2] = quadratic(a, b, c)
% Return the roots of a*x^2 + b*x + c.
% Roots may be complex.

d = disc(a, b, c);
x1 = (-b + sqrt(d)) / (2*a);
x2 = (-b - sqrt(d)) / (2*a);
end

function dis = disc(a,b,c) 
% dis = disc(a,b,c)
% Return the discriminant of a, b, c.
dis = b^2 - 4*a*c;
end