I need help

Consider the function f(a:) 2 12:55 + 459:41 360:1:3 + 5. f(a:) has inflection points at (reading from left to right) x = D, E, and F For each of the following intervals, tell whether f(m) is concave up or concave down. oo,D)= co): ): ): 9 ED, E (E F ( .p _ F