There are no dedicated keys for these trigonometric functions, for the simple reason that they can be obtained from the tan, sin, and cos by a simple division.cotangent (x) =1/tan(x) .
Do not confuse with the arc tangent tan^(-1)cosecant (x)
= 1/sin(x) . Do not confuse with the arcsine sin^(-1)secant(x)
=1/cos(x) Do not confuse with the arccosine cos^(-10)
If you know how to use the tan, cos, and sin, with angle unit in degrees or radians, then there will not be any problem
If angle unit is degree, any number you give a trigonometric function is interpreted as degree. For instance if mode is in degree , and you calculate cos(PI) do not expect the value -1. You will have the value corresponding to the cosine of of 3.14159 degrees, namely 0.99849715
Now for you if you are interested.
If [MODE] is in degrees you can still enter angles in radians
You use the [2nd][ANGLE] [3: raised r] [ENTeR].
Here is a screen capture to show you more clearly.
The raised r is obtained by [2nd][ANGLE][3: raised r] [ENTER]
Hope it helps.