The word trigonometry is derived from the Greek words tri = three, gon = sides and metron = measure.
- sin θ = A/H
- cos θ = O/H
- tan θ = A/O
- cosec θ = H/A
- sec θ = H/O
- cot θ = O/A
Reciprocal Identities |
sin θ =
|
csc θ =
|
cos θ =
|
sec θ =
|
tan θ =
|
cot θ =
|
Quotient Identities |
tan θ =
|
cot θ =
|
Pythagorean Identities |
Sin2θ + Cos2θ = 1 |
Sec2θ - Tan2θ = 1 |
Cosec2θ - Cot2θ = 1 |
Trigonometry Ratios:
Degrees |
00 |
300 |
450 |
600 |
900 |
1800 |
2700 |
3600 |
Radions |
0 |
π/6 |
π/4 |
π/3 |
π/2 |
π |
3π/2 |
2π |
Sin θ |
0 |
1/2 |
|
|
1 |
0 |
-1 |
0 |
Cos θ |
1 |
|
|
1/2 |
0 |
-1 |
0 |
1 |
Tan θ |
0 |
|
1 |
|
∞ |
0 |
∞ |
0 |
Cot θ |
∞ |
|
1 |
|
0 |
∞ |
0 |
∞ |
Sec θ |
1 |
|
|
2 |
∞ |
-1 |
∞ |
1 |
Cosec θ |
∞ |
2 |
|
|
1 |
∞ |
-1 |
∞ |