To send international first class mail (large envelopes) from the United States to Australia in 2010, it cost $1.24 for the first ounce, $0.84 for each additional ounce up to a total of 8 oz, and $1.72 for each additional four ounces after that up to a total of 64 oz. Let C(x) be the cost to mail x ounces. Find the following.

a.

b.

c.

d. c(3)

e.

f.

g.

h. C(14)

i. Find all values on the interval (0, 64) where the function C is discontinuous.

lim C(x) x3