如何找到2条曲线之间的交点

Question

我一直试图找到2条曲线之间的交点，我的公式很长，而且我不知道如何在x轴找到该值

这是我的代码：

    Dr = (0:0.001:7);

    a1 = (2*Dr + t)/t;
    b1 = (h - 1.45*Dr)/t;
    c1 = (h - k4*Dr)/t;
    d1 = a1.*b1;
    e1 = d1.*c1;
    Fs1 = Dr.*((4000*E/(1 - v^2))*(t^3 / Do^2)*(k2/k1)*(1 + 0.153*e1));
    Fs1 = double(Fs1);

    a2 = ((Dr-dss)*ks - 0.1*t)/t;
    b2 = (h - 2.2*(Dr-dss)*ks)/t;
    c2 = (h - K4*(Dr-dss)*ks)/t;
    d2 = a2.*b2;
    e2 = d2.*c2;
    f = (Dr -dss)*ks;
    Fb2 = f.*((250*E/(1 - v^2))*(t^3 / (k1*Do^2))*(1 + 0.133*e2));

    n = ks*Fb2;
    n = double(n);
    n(Dr<3.47)=0;

    plot (Dr,n,Dr,Fs1)
    ylim([0 600]);
    grid on;