A. Tangent, Sine, and Cosine Ratios
Completion requirements
In Lesson 3.1, you saw that a table of tangent ratios could be made and used to determine unknowns. The following table shows the tangent, sine, and cosine ratios for various angles. All values are approximate.
θ | tan θ | sin θ | cos θ |
---|---|---|---|
5° | 0.09 | 0.09 | 0.996 |
10° | 0.18 | 0.17 | 0.98 |
15° | 0.27 | 0.26 | 0.97 |
20° | 0.36 | 0.34 | 0.94 |
25° | 0.47 | 0.42 | 0.91 |
30° | 0.58 | 0.5 | 0.87 |
35° | 0.70 | 0.57 | 0.82 |
40° | 0.84 | 0.64 | 0.77 |
45° | 1 | 0.71 | 0.71 |
50° | 1.19 | 0.77 | 0.64 |
55° | 1.43 | 0.82 | 0.57 |
60° | 1.73 | 0.87 | 0.5 |
65° | 2.14 | 0.91 | 0.42 |
70° | 2.75 | 0.94 | 0.34 |
75° | 3.73 | 0.97 | 0.26 |
80° | 5.67 | 0.98 | 0.17 |
85° | 11.43 | 0.996 | 0.09 |
Again, use of the table is limited to problems involving the angles and ratios listed. Alternatively, the sin, sin-1, cos, cos-1, tan, and tan-1 functions on a calculator can be used with any ratio or angle.