Integrating the following delta dirac function should yield min(t,s), but how?

[Bablo]

Homework Statement

I need to understand how to integrate
$$\int_{0}^{t}\int_{0}^{s} \delta(\tau-\tau')d\tau d\tau'$$
The solution is $$min(t,s)$$

Homework Equations

See above

The Attempt at a Solution

$$min(t,s)$$

 

[lanedance]

hey Bablo

have you tried considering each of the cases separately (s>t,s<t)? then you can change the order of integration and integrate directly...