Exercise 5.7 .8 Sales in the Web-hosting industry are projected to grow in accordance with the function f(t) : 0.05r3 + 0.56:2 + 5.47: + 1.5 0 g r g 6 where f(t) is measured in billions of dollars and t is measured in years, with t = 0 corresponding to I 999. (0) Find the interval where f is increasing and the interval where f is decreasing. (b) What does your result tell you about the sales in the Web-hosting industry from 1999 through 2005