The sales of a book publication are expected to grow according to the function S= XXXXXXXXXX−e−0.06t),where t is the time,given in days. (i) Show using differentiation that the sales never attains an...

The sales of a book publication are expected to grow according to the function S=300000(1−e−0.06t),where t is the time,given in days.
(i) Show using differentiation that the sales never attains an exact maximum value.

(ii) What is the limiting value approached by the sales function?