Analysis of the daily output of a factory shows that, on average, the number of units per hour y produced after t hours of production is y = 24t + 0.5t^2 - t^3, 0 ≤ t ≤ 5. For which values of t, for 0 ≤ t ≤ 5, is y increasing? (Enter your answer using interval notation.)
Consider the function f(x) = (1/3)x^3 + x^2 - 35x + 25. Find the relative maxima, relative minima, and horizontal points of inflection. (If an answer does not exist, enter DNE.)