Almost half of companies let other firms manage some of their web operations a practice called web hosting. Managed services monitoring a customer's technology services is the fastest growing part of web hosting. Managed services sales are approximated by the function f(t)=0.469t^2+0.758t+0.44 where f(t) is measured in billions of dollars and t is mearsured in years with t=0 correspondinf to 1999. Find the interval where f is increasing?