17.3 Trigonometry
Octave provides the following trigonometric functions.  Angles are
specified in radians.  To convert from degrees to radians multiply by
pi/180
 (e.g. sin (30 * pi/180) returns the sine of 30 degrees).
   
— Mapping Function:  
sin (
x)
Compute the sine of each element of x. 
— Mapping Function:  
cos (
x)
Compute the cosine of each element of x. 
— Mapping Function:  
tan (
z)
Compute tangent of each element of x. 
— Mapping Function:  
sec (
x)
Compute the secant of each element of x. 
— Mapping Function:  
csc (
x)
Compute the cosecant of each element of x. 
— Mapping Function:  
cot (
x)
Compute the cotangent of each element of x. 
— Mapping Function:  
asin (
x)
Compute the inverse sine of each element of x. 
— Mapping Function:  
acos (
x)
Compute the inverse cosine of each element of x. 
— Mapping Function:  
atan (
x)
Compute the inverse tangent of each element of x. 
— Mapping Function:  
asec (
x)
Compute the inverse secant of each element of x. 
— Mapping Function:  
acsc (
x)
Compute the inverse cosecant of each element of x. 
— Mapping Function:  
acot (
x)
Compute the inverse cotangent of each element of x. 
— Mapping Function:  
sinh (
x)
Compute the hyperbolic sine of each element of x. 
— Mapping Function:  
cosh (
x)
Compute the hyperbolic cosine of each element of x. 
— Mapping Function:  
tanh (
x)
Compute hyperbolic tangent of each element of x. 
— Mapping Function:  
sech (
x)
Compute the hyperbolic secant of each element of x. 
— Mapping Function:  
csch (
x)
Compute the hyperbolic cosecant of each element of x. 
— Mapping Function:  
coth (
x)
Compute the hyperbolic cotangent of each element of x. 
— Mapping Function:  
asinh (
x)
Compute the inverse hyperbolic sine of each element of x. 
— Mapping Function:  
acosh (
x)
Compute the inverse hyperbolic cosine of each element of x. 
— Mapping Function:  
atanh (
x)
Compute the inverse hyperbolic tangent of each element of x. 
— Mapping Function:  
asech (
x)
Compute the inverse hyperbolic secant of each element of x. 
— Mapping Function:  
acsch (
x)
Compute the inverse hyperbolic cosecant of each element of x. 
— Mapping Function:  
acoth (
x)
Compute the inverse hyperbolic cotangent of each element of x. 
Each of these functions expects a single argument.  For matrix arguments,
they work on an element by element basis.  For example,
     sin ([1, 2; 3, 4])
            0.84147   0.90930
              0.14112  -0.75680
   
— Mapping Function:  
atan2 (
y, x)
Compute atan (y / x) for corresponding elements of y
and x.  The result is in range -pi to pi. 
In addition to the trigonometric functions that work with radians,
Octave also provides the following functions which work with degrees.
   
— Function File:  
sind (
x)
Compute the sine of each element of x.  Returns zero in elements
for which x/180 is an integer.
        
     
     
     See also: sin, cosd, tand, acosd, asind, atand. 
— Function File:  
cosd (
x)
Compute the cosine of an angle in degrees.  Returns zero in elements
for which (x-90)/180 is an integer.
        
     
     
     See also: cos, sind, tand, acosd, asind, atand. 
— Function File:  
tand (
x)
Compute the tangent of an angle in degrees.  Returns zero for elements
of for which x/180 is an integer and Inf for elements
where (x-90)/180 is an integer.
        
     
     
     See also: tan, cosd, sind, acosd, asind, atand. 
— Function File:  
secd (
x)
Compute the secant of an angle in degrees.
        
     
     
     See also: sec, cscd, sind, cosd. 
— Function File:  
cscd (
x)
Compute the cosecant of an angle in degrees.
        
     
     
     See also: csc, secd, sind, cosd. 
— Function File:  
cotd (
x)
Compute the cotangent of an angle in degrees.
        
     
     
     See also: cot, tand. 
— Function File:  
asind (
x)
Compute the inverse sine of an angle in degrees.
        
     
     
     See also: asin, sind, acosd. 
— Function File:  
acosd (
x)
Compute the inverse cosine of an angle in degrees.
        
     
     
     See also: acos, cosd, asecd. 
— Function File:  
atand (
x)
Compute the inverse tangent of an angle in degrees.
        
     
     
     See also: acot, tand. 
— Function File:  
asecd (
x)
Compute inverse secant in degrees.
        
     
     
     See also: asec, secd, acscd. 
— Function File:  
acscd (
x)
Compute the inverse cosecant of an angle in degrees.
        
     
     
     See also: acsc, cscd, asecd. 
— Function File:  
acotd (
x)
Compute the inverse cotangent of an angle in degrees.
        
     
     
     See also: atan, tand.