
Since I noticed I had to keep looking some of these up, I place them here, just for reference, gathered from around the internet. Many of these formulas can be written in different ways, but I have simplified them as much as possible.
Where,
a | sin(a) = cos(b) = sin(90-b) = cos(90-a) | tan(a) = cot(b) = tan(90-b) = cot(90-a) | b | ||
---|---|---|---|---|---|
deg | rad | deg | rad | ||
0 | 0 | 0 | 0 | 90 | π/2 |
3 | π/60 | 87 | 29π/30 | ||
6 | π/30 | 84 | 7π/15 | ||
9 | π/20 | 81 | 9π/20 | ||
12 | π/15 | 78 | 13π/30 | ||
15 | π/12 | 75 | 5π/12 | ||
18 | π/10 | 72 | 2π/5 | ||
21 | 7π/60 | 69 | 23π/60 | ||
22.5 | π/8 | 67.5 | 3π/8 | ||
24 | 2π/15 | 66 | 11π/30 | ||
27 | 3π/20 | 63 | 7π/20 | ||
30 | π/6 | 60 | π/3 | ||
33 | 11π/60 | 57 | 19π/60 | ||
36 | π/5 | 54 | 3π/10 | ||
39 | 13π/60 | 51 | 17π/60 | ||
42 | 7π/30 | 48 | 4π/15 | ||
45 | π/4 | 1 | 45 | π/4 | |
48 | 4π/15 | 42 | 7π/30 | ||
51 | 17π/60 | 39 | 13π/60 | ||
54 | 3π/10 | 36 | π/5 | ||
57 | 19π/60 | 33 | 11π/60 | ||
60 | π/3 | 30 | π/6 | ||
63 | 7π/20 | 27 | 3π/20 | ||
66 | 11π/30 | 24 | 2π/15 | ||
67.5 | 3π/8 | 22.5 | π/8 | ||
69 | 23π/60 | 21 | 7π/60 | ||
72 | 2π/5 | 18 | π/10 | ||
75 | 5π/12 | 15 | π/12 | ||
78 | 13π/30 | 12 | π/15 | ||
81 | 9π/20 | 9 | π/20 | ||
84 | 7π/15 | 6 | π/30 | ||
87 | 29π/30 | 3 | π/60 | ||
90 | π/2 | 1 | 0 | 0 | |
deg | rad | sin(a) = cos(b) = sin(90-b) = cos(90-a) | tan(a) = cot(b) = tan(90-b) = cot(90-a) | deg | rad |
a | b |
The values for angles outside the range 0-90 degrees, can be found by reducing the angle be in the correct range. Negative angles should have 360 added to them until positive. If angle ≥360, subtract multiples of 360 from it, until <360. Then, if angle ≥270, subtract from 360. If angle ≥180, subtract 180. If angle ≥90, subtract from 180.
Examples:
- sin(-54)=sin(360-54)=sin(306)=-sin(54)
- cos(120)=cos(180-120)=-cos(60)
- tan(225)=tan(225-180)=tan(45)
- tan(-225)=tan(360-225)=tan(135)=tan(180-135)=-tan(45)
- sin(1000)=sin(1000-360*2)=sin(280)=sin(360-280)=-sin(80)
Angles between 0 and 360 will have the following signs and are measured in a counter-clockwise arc originating at the “x+” line.
FYI, here is the exact value of sin 1°,
and the cos 1°,