is exp z / sin z a pole or singularities or neither ??
applying pole test,
(z-0)( exp z / sin z)
= z*expz / sin z
sub 0 into equation, achieve 0 / 0,
using hopital rule, i get ( z*exp z + exp z ) / cos z
= 1 <--- can i conclued it's a pole ?
If i have to apply hopital rule and achieve a constant, does that mean that it's always a RS ??
many thanks ?