Sec, Cosec and Cot
Secant, cosecant and cotangent, almost always written as sec, cosec and cot are trigonometric functions like sin, cos and tan.
sec x = 1
cosec x = 1
cot x = 1 = cos x
tan x sin x
Note, sec x is not the same as cos-1x (sometimes written as arccos x).
Remember, you cannot divide by zero and so these definitions are only valid when the denominators are not zero.
If sec x = 2, cos x = ½, x = 60º
Graphs of sec x and cosec x