7.0 r2' where t is time in years. The graphs of P, P', and P\" are 1 + 5.40.2)" The number of research articles in a prominent journal that were written by researchers in Europe can be modeled by P(t) = shown here. Graph of P p Graph of P' 71' P' 0.20 - el 5 0.15 4 0.10 3i 2L 0.05 1 o_.__._._._._._._._l_._.___l__._._._a t 0_00__._._._l_._._._._._._._._._l_.__.__; t 0 10 20 30 40 0 10 20 30 40 Graph of P" P" 0.010 0.005 0.000 t 10 30 40 _n on: / _ 0.005 \\_/ 0.010 Determine to the nearest whole number the values of t for which the graph of P is concave up and where it is concave down, and locate any points of inflection. concave up 0 J