Hi. Sorry I couldn't think of a more appropriate title for this thread. I'm doing some calculatons and I arrived at an equation with this form [tex] f(t')|_0^t = \int_0^t f(t')dt' [/tex] I was just wondering if anyone as any insight into the interpretation of such an expression. All I can think of is the obvious: that the difference between the function f(t) at the endpoints must equal the area under the curve f(t) between those endpoints. I guess what I'm asking is, what characteristics must f(t) have in order to satisfy this. Moreover, and probably importantly, I only need this to hold from SOME value of t, not ALL values of t. Thanks.