Need help on the last question

Suppose that profits on the sale of swimming suits in a department store over a 2-year period are given approximately by P(t) = 5-5 cos 26 , Osts 104 where P is profit (in hundreds of dollars) for a week of sales t weeks after January 1. The graph of the profit function is shown in the figure. (A) Find the exact values of the following without using a calculator. P(13) = 5 P(26) = 10 P(39) = 5 P(52) = 0 (B) Use a calculator to find the following. P(36) = (Round to three decimal places as needed.)