Which of the following lists does not include all the factors of the number? a. 10: 1, 2, 5, 10 b. 5: 1, 5 c. 4: 1, 2, 4 d. 21: 1, 21

D because you can also do 7 times 3

Hello! i hope this
since the cosine is the ratio of the adjacent side to the hypotenuse, you can see that cos 60° = ½. answer. according to the property of cofunctions (topic 3), sin 30° is equal to cos 60°. sin 30° = ½.