A funny joke is spreading through the office. The speed that it is spreading can be modelled by the equation f(x) = 4 + e^x, where x is the time in minutes and x 0.
a Find out many employees heard the joke initially
b Find how many minutes it took before 150 employees heard the joke
+37158 At x = 0
f(x) = 4 + e0 = 4 employees initially
150 = 4 + ex
146 = e^x
ln (146) = x = 4.98 ~~~ 5 minutes
