Numerical Methods

quadratic equation

by 蔡 育曄

JavaScript

var x,y;

function solve (p1,q1,p2,q2,r1,s1,r2,s2) {
	x=(p1*(r1*s2-r2*s1)+p2*(r2*s1-r1*s2)+p1*q2*(r2-r1)+p2*q1*(r1-r2))/(p1*(s2-s1)+p2*(s1-s2)+q2*(r2-r1)+q1*(r1-r2));
  y =(q2*(p1*(s2-s1)-r1*s2+r2*s1)+q1*(r1*s2+p2*(s1-s2)-r2*s1))/(p1*(s2-s1)+p2*(s1-s2)+q2*(r2-r1)+q1*(r1-r2));
  return [x,y];
}

var roots = solve(0,5,4,2,0,3,6,0);
//console.log (roots);
if (roots.length === 0)
    console.log ('no real roots');
else 
    console.log ('x: ' + roots[0] + '; ' + 
                 'y: ' + roots[1]);