(1 point) The rate at which a machine operator's efficiency, E(t) (expressed as a percentage), changes with respect to time t is given by dE _ _ 1 dt 33 6: where t is the number of hours the operator has been at work. (A) Find EU), given that the operator's efficiency after working 2 hours is 80% that is, E(2) = 80. Operator's efficiency function E0) = (B) What is the operator's efficiency after 6 hours