12.2 5 Find the largest open intervals on # 27 which each function is concave upward or concave downward and find the location of any points of inflection. FC x ) = X ' + 41 x 2 - 6 x + 3 Find all critical numbers of the functions, Then use the second - derivative + on each critical number to determine whether F43 it leads to a local maximum or minimum f ( x ) = x t - X