import java.util.*;
public class prob7{
    public static int p,q,r,s,t,u;
    public static double f(int x){
        return p*Math.exp(-x) + q*Math.sin(x)+r*Math.cos(x)+s*Math.tan(x)+t*x*x+u;
    }
    public static int bi(){
        int low=0;
        int high=1;
        while(low+high>0.0000001){
            int x=(low+high)/2;
            if(f(low)*f(x)<=0){
                high=x;
            }
            else{
                low=x;
            }
        }
        return (low+high)/2;
    }

    public static void main(String args[]){
        Scanner input=new Scanner(System.in);
        int n=input.nextInt();
        while(n>0){
            p=input.nextInt();
            q=input.nextInt();
            r=input.nextInt();
            s=input.nextInt();
            t=input.nextInt();
            u=input.nextInt();
            if(f(0)*f(1)>0){
                System.out.println("Impossivel");
            }
            else{
                double out=bi();
                System.out.printf("%.4lf\n", out);
            }
            n--;
        }


}
}