How do I pull a value out of a different equation @ a specific value

I am trying to find the value of D @ time Tmin but in my mind I think it should go like Tmin(D) but it says indices must be positive intgers or logical values.

function[Tmin,Dt] = Tension(Lb,Lc,W,Dmin,Dmax)
D = linspace(Dmin,Dmax,20);
T = (Lb*Lc*W)./(D.*sqrt(Lc^2-D.^2));
Tmin = min(T);
Dt = T(Tmin);

Answer 1

[James Tursa]

[Tmin,k] = min(T);
Dt = D(k);

[Bryce Johnson]

Thanks I just couldn't figure it out, also I replaced Dmin with Dt because Dmin is already specified in the function input but that still worked.