1) Find the cost function if the marginal cost function is given by C'(x)= x^(3/4) + 5 and 16 units cost $212.

2) The approximate rate of change in the number (in billions) of monthly text messages is given by the equation f'(t) = 6.8t -15.9 where t represents the number of years since 2000. In 2002 (t=2) there were approximately 9.9 billion monthly text messages. Find the function that gives the total number (in billions) of monthly text messages in year t.