The gure above shows the graph of f', the derivative of a twice-differentiable function f, on the interval [3. 4]. Answer the following questions based on the graph of f '. a) Find all I-COOFdinatBS at which f has a relative minimum. Justify your answer. b} On what open intervals contained in [3, 4] is the graph of f both concave up and decreasing? Justify your answer. c) Find the xooordinates of all points of inection on the graph off. d} What is the average rate of change of f ' between I = 0 and x = 3