Answer: False
Step-by-step explanation:
False, the value of cosine at pi and 2pi is equal to -1 and 1 respectively. You can test this by using the pi circle or a calculator. Let pi = 180 degrees. Cosine is always defined and alternates between 1 and -1.
Answer:
D
560
10 x 9 = 90 x 6 = 560