First-class postage is $0.38 for a letter weighing up to one ounce and $0.21 for each additional ounce (or fraction thereof). For example, the cost of postage for 1 ounce would be $0.38 and cost for 1.36 ounces would be $0.59. Let C(x) represent the cost of postage for a letter weighing x ounces. Use this information to answer the questions below. Write "DNE" if the limit does not exist or the function value is undefined. lim C(x)= x-3 lim C(x) = x-3+ lim C(x)= x+3 C(3) = Find all x-values on the interval (0, 4) where the function is discontinuous. Separate multiple answers with a comma.