1. The problem statement, all variables and given/known data what is the limit of yb(t) as \delta goes to zero. yb(t) = (b/delta)*exp[-t/RC](exp[delta/RC] - 1)(u(t)-u(t-delta)) b=1. 2. The attempt at a solution I used L'hopitals rule to find the limit of (b/delta)*exp[-t/RC](exp[delta/RC] - 1), which i got to be exp[-t/RC]/RC. But I do not know what to do with the u(t)-u(t-delta). does it go to zero? or am I supposed to say it goes to delta(t)? Any help/ advice would be appreciated, thanks!