3 ms·
Let t -> 1 which you can do because this entire trick is about interchanging limits (since both an integral and a derivative are limits)
by anon_tor_12345 6y ago
Let t -> 1 which you can do because this entire trick is about interchanging limits (since both an integral and a derivative are limits)
- goerz 6y agoAh, thanks! So it's just "has to hold for all values of t > 0, including for t = 1"