Please help with the two i got wrong

Consider the function below. (If an answer does not exist, enter DNE.) F(x) - XV 18 - x (a) Find the interval of increase. (Enter your answer using interval notation.) (-00,12) Find the interval of decrease. (Enter your answer using interval notation.) (12,18 ) (b) Find the local minimum value(s). (Enter your answers as a comma-separated list.) DNE Find the local maximum value(s). (Enter your answers as a comma-separated list.) DNE (c) Find the inflection point. ( x, y) = DNE Find the interval where the graph is concave upward. (Enter your answer using interval notation. ) (00, 18 X