# Calculus

posted by
**Evan** on
.

S'(t)= -147.78e^(-0.2t)

S=7389 units when t=0

find the function that describes the number of daily sales t days after the end of the campaign

Really stuck can someone help me to just find the function so I can head in the right track for the rest of the question

let f(t)= e^kt + C

then f'(t)= k e^kt

so here you are given S', integrate to get S. Don't forget the constant of integration.