squarequation.txt

这是一本java基础教程 对新手上路有很大帮助

package tom.jiafei;
public class SquareEquation{
    double a,b,c;
    double root1,root2;
    boolean boo;
    public SquareEquation(double a,double b,double c){
       this.a=a;
       this.b=b;
       this.c=c;
       if(a!=0){
          boo=true;
       }    
       else{
          boo=false;
       }
    }
    public void getRoots(){
       if(boo){
          System.out.println("是一元2次方程");
          double disk=b*b-4*a*c;
          if(disk>=0){
             root1=(-b+Math.sqrt(disk))/(2*a);
             root2=(-b-Math.sqrt(disk))/(2*a);
             System.out.printf("方程的根:%f,%f\n",root1,root2);
          } 
          else{
             System.out.printf("方程没有实根\n");
          }
       }
       else{
           System.out.println("不是一元2次方程");
       }
    } 
    public void setCoefficient(double a,double b,double c){
       this.a=a;
       this.b=b;
       this.c=c;
       if(a!=0){
          boo=true;
       }    
       else{
           boo=false;
       }
    }
}