A psychologist contends that the number of facts of a certain type that are remembered after t hours is given by the following function. 91t f(t ) 99t - 91 Find the rate of change at which the number of facts remembered is changing after 1 hour and after 10 hours. The rate of change after 1 hour is about facts/hour. (Round to the nearest integer as needed.) The rate of change after 10 hours is about facts/hour (Round to the nearest integer as needed.)