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 seperately (s>t,s<t)? then you can change the order of integration and integrate directly...