#include <bits/stdc++.h>

using i64 = long long;

void solve() {
    int a, b;
    std::cin >> a >> b;
    
    int xA, yA, xB, yB, xC, yC;
    std::cin >> xA >> yA >> xB >> yB >> xC >> yC;
    
    if (xB > xC) {
        xA *= -1;
        xB *= -1;
        xC *= -1;
    }
    if (yB > yC) {
        yA *= -1;
        yB *= -1;
        yC *= -1;
    }
    
    int dAB = std::abs(xA - xB) + std::abs(yA - yB);
    int dAC = std::abs(xA - xC) + std::abs(yA - yC);
    int dBC = std::abs(xB - xC) + std::abs(yB - yC);
    double ans = 1.0 * dAC / a;
    
    if (dAB + dAC == dBC) {
        ans = std::min(ans, 1.0 * dBC / b);
    } else if (dAB + dBC == dAC) {
        double d = 1.0 * dAB / (a + b) * b;
        ans = std::min(ans, (2 * d + dBC) / b);
    } else if (dAC + dBC == dAB) {
        double d = 1.0 * dAB / (a + b) * b;
        if (d >= dBC) {
            ans = std::min(ans, (2 * d - dBC) / b);
        }
    } else {
        double dAD = (1.0 * dAB + dAC - dBC) / 2;
        double dBD = dAB - dAD;
        if (dAD / a < dBD / b) {
            ans = std::min(ans, 1.0 * dBC / b);
        } else {
            double d = 1.0 * dAB / (a + b) * b;
            ans = std::min(ans, (1.0 * dBC + 2 * (d - dBD)) / b);
        }
    }
    
    std::cout << ans << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    std::cout << std::fixed << std::setprecision(10);
    
    int t;
    std::cin >> t;
    
    while (t--) {
        solve();
    }
    
    return 0;
}