Almost half of companies let other firms manage some of their web operations - a practice called web hosting. managed services - monitoring customer's technology services - is the fastest growing part of web hosting. managed services sales are approximated by the function f(t) = 0.469t2 + 0.758t + 0.44 (0 < t < 10) where f(t) is measured in billions of dollars and t is measured in years, with t = 0 corresponding to 1999. + find the interval where f is increasing. (enter your answer using interval notation.) the u. s. public debt outstanding from 1990 through 2011 is approximated by 0(t) = 0.0032^ - 0.0698 2 + 0.6048f + 3.22 (0 < t < 21) trillion dollars in year t, with t = 0 corresponding to 1990. + show that 0'(t) > 0 for all t in the interval (0, 21).