- 1. Describe the unit circle.
- 2. What do the x- and y-coordinates of the points on the unit circle represent?
3. Discuss the difference between a coterminal angle and a reference angle.
4. Explain how the cosine of an angle in the second quadrant differs from the cosine of its reference angle in the unit circle.
5. Explain how the sine of an angle in the second quadrant differs from the sine of its reference angle in the unit circle.
For the following exercises, use the given sign of the sine and cosine functions to find the quadrant in which the terminal point determined by t lies.
6. sin(t)<0 and cos(t)<0 7. sin(t)>0 and cos(t)>0
8. sin(t)>0 and cos(t)<0 9. sin(t)<0 and cos(t)>0
For the following exercises, find the exact value of each trigonometric function.
10. sinπ2
11. sinπ3
12. cosπ2
13. cosπ3
14. sinπ4
15. cosπ4
16. sinπ6
17. sinπ
18. sin3π2
19. cosπ
20. cos0
21. cosπ6
22. sin0
For the following exercises, state the reference angle for the given angle.
23. 240∘
24. −170∘
25. 100∘
26. −315∘
27. 135∘
28. 5π4
29. 2π3
30. 5π6
31. −11π3
32. −7π4
33. −π8
For the following exercises, find the reference angle, the quadrant of the terminal side, and the sine and cosine of each angle. If the angle is not one of the angles on the unit circle, use a calculator and round to three decimal places.
34. 225∘
35. 300∘
36. 320∘
37. 135∘
38. 210∘
39. 120∘
40. 250∘
41. 150∘
42. 5π4
43. 7π6
44. 5π3
45. 3π4
46. 4π3
47. 2π3
48. 5π6
49. 7π4
For the following exercises, find the requested value.
50. If cos(t)=17 and t is in the 4th quadrant, find sin(t).
51. If cos(t)=29 and t is in the 1st quadrant, find sin(t).
52. If sin(t)=38 and t is in the 2nd quadrant, find cos(t).
53. If sin(t)=−14 and t is in the 3rd quadrant, find cos(t).
54. Find the coordinates of the point on a circle with radius 15 corresponding to an angle of 220∘.
55. Find the coordinates of the point on a circle with radius 20 corresponding to an angle of 120∘.
56. Find the coordinates of the point on a circle with radius 8 corresponding to an angle of 7π4.
57. Find the coordinates of the point on a circle with radius 16 corresponding to an angle of 5π9.
58. State the domain of the sine and cosine functions.
59. State the range of the sine and cosine functions.
For the following exercises, use the given point on the unit circle to find the value of the sine and cosine of t.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
For the following exercises, use a graphing calculator to evaluate.80. sin5π9
81. cos5π9
82. sinπ10
83. cosπ10
84. sin3π4
85. cos3π4
86. sin98∘
87. cos98∘
88. cos310∘
89. sin310∘
Find the exact value for each of the following products.
90. sin(11π3)⋅cos(−5π6)
91. sin(3π4)⋅cos(5π3)
92. sin(−4π3)⋅cos(π2)
93. sin(−9π4)⋅cos(−π6)
94. sin(π6)⋅cos(−π3)
95. sin(7π4)⋅cos(−2π3)
96. cos(5π6)⋅cos(2π3)
97. cos(−π3)⋅cos(π4)
98. sin(−5π4)⋅sin(11π6)
99. sin(π)⋅sin(π6)
For the following exercises, use this scenario: A child enters a carousel that takes one minute to revolve once around. The child enters at the point (0,1), that is, on the due north position. Assume the carousel revolves counter clockwise.
100. What are the coordinates of the child after 45 seconds?
101. What are the coordinates of the child after 90 seconds?
102. What is the coordinates of the child after 125 seconds?
103. When will the child have coordinates (0.707,−0.707) if the ride lasts 6 minutes? (There are multiple answers.)
104. When will the child have coordinates (−0.866,−0.5) if the ride last 6 minutes?
Candela Citations
- Precalculus. Authored by: Jay Abramson, et al.. Provided by: OpenStax. Located at: http://cnx.org/contents/fd53eae1-fa23-47c7-bb1b-972349835c3c@5.175:1/Preface. License: CC BY: Attribution. License Terms: Download for free at: http://cnx.org/contents/fd53eae1-fa23-47c7-bb1b-972349835c3c@5.175:1/Preface