1 to the power any real number is always one. Also, the value of (r/very large number) is very close to 1 but not equal to it. So, in this case, you would have to use limits (which isn’t covered in the CFA course, so dont worry about it) and the FV value will be equal to:
FV=PV*e^(rN)
which is nothing but the case of continuous compounding.