 
 
 
5.24.1  Trigonometric functions
- 
sin  is the sine function,
- cos  is the cosine function,
- tan  is the tangent function (tan(x)=
sin(x)/cos(x)),
- cot  is the cotangent function (cot(x)=
cos(x)/sin(x)),
- sec  is the secant function (sec(x)=
1/cos(x)),
- csc  is the cosecant function (csc(x) =
1/sin(x)),
- asin or arcsin, acos or arccos, atan or arctan, acot, asec, acsc
are the inverse trigonometric functions. The latter are defined by:
- 
asec(x) = acos(1/x), 
- acsc(x) = asin(1/x),
- acot(x) = atan(1/x). 
 
 
 
