Consider the equation below. (If an answer does not exist, enter DNE.) f(x) = e3x + e-x (a) Find the interval on which f is increasing. (Enter your answer using interval notation.) In(3) 4 Find the interval on which f is decreasing. (Enter your answer using interval notation.) In(3) - 4 (b) Find the local minimum and maximum values of f. local minimum value local maximum value (c) Find the inflection point. (x, y) = ( DNE Find the interval on which f is concave up. (Enter your answer using interval notation.) (-0,00) Find the interval on which f is concave down. (Enter your answer using interval notation.) DNE