1.A piece of charcoal is found to contain 39% of the element B that it originally had.

(a) When did the tree from which the charcoal came die? Use 5800 years as the half-life of the element B.

(b) Using a graphing utility, graph the relation between the percentage of the element B remaining and time.

(c) Using INTERSECT, determine the time that elapses until half of the the element B remains.

(d) Verify the answer found in part (a).

2.A pizza baked at 400 degrees F is removed from the oven at 8:00PM into a room that is a constant 73 degrees F. After 5 minutes, the pizza is at 300 degrees F.

(a) At what time can you begin eating the pizza if you want its temperature to be 130 degrees F?

(b) Using a graphing utility, graph the relation between temperature and time.

(c) Using INTERSECT, determine the time that needs to elapse before the pizza is 160 degrees F.

(d) TRACE the function for large values of time. What do you notice about y, the temperature?