\f(a) At what values of X do the local maximum values of 9 occur? (Enter your answers as a comma-separated list.) X: K At what values of X do the local minimum values of 9 occur? (Enter your answers as a commaseparated list.) X (b) Where does 9 attain its absolute maximum value? x: x On what intervals is g concave downward? {Enter your answer using interval notation.) X (c) Sketch the graph of g. 0 J X 6 12 18 24 30 X 6 12 18 30 O i