- Secant (sec) is the reciprocal of cosine (cos):
- Cosecant (cosec) is the reciprocal of sin:
- Cotangent (cot) is the reciprocal of tan:
Recall, in case of a right angle triangle if we are given one length and one angle and we have to find a missing length or if we need to find a missing angle when two lengths are given we use SOH/CAH/TOA where:
SOH is shown in Fig 2
CAH is shown in Fig 3
TOA is applies to both Fig 2 & Fig 3
However, there are more trigonometric functions i.e
Note: Remember that is not the inverse of and cannot be written as . This also applies to and .
- Secant (sec) is the reciprocal of cosine (cos)
- Cosecant (cosec) is the reciprocal of sin
- Cotangent (cot) is the reciprocal of tan
Q. In the triangle, find cosec(A), sec(A), and cot(A).
If we need to find out the angle A, we simply choose one of the above functions i.e
We know that: