jelon2_v1

#include<iostream>
#include<math.h>
#include<bits/stdc++.h>
int main()
{
    unsigned long int A, B, C, T;
    double D;
    std::cin>>T;
    for(int ti=0; ti<T; ti++)
    {
        std::cin>>A>>B>>C;

        double x=0;
        double step=10;
        int dir=0;
        do
        {
            D = A * x + B * sin(x) - C;
            //D = A * x + B * sin(x) + C;
            if(D>0)
            {
                if(dir>0) step/=2;
                dir=-1;
                x-=step;
            }
            else
            {
                if(dir<0) step/=2;
                dir=1;
                x+=step;
            }
        } while(abs(D)>0.0000001);
        std::cout<<std::fixed << std::setprecision(6)<<x<<std::endl;
    }


    return 0;
}