The GNU C Library
19.5 Hyperbolic Functions
The functions in this section are related to the exponential functions;
see 19.4 Exponentiation and Logarithms.
 Function: double sinh (double x)

 Function: float sinhf (float x)

 Function: long double sinhl (long double x)
 These functions return the hyperbolic sine of x, defined
mathematically as
(exp (x)  exp (x)) / 2
. They
may signal overflow if x is too large.
 Function: double cosh (double x)

 Function: float coshf (float x)

 Function: long double coshl (long double x)
 These function return the hyperbolic cosine of x,
defined mathematically as
(exp (x) + exp (x)) / 2
.
They may signal overflow if x is too large.
 Function: double tanh (double x)

 Function: float tanhf (float x)

 Function: long double tanhl (long double x)
 These functions return the hyperbolic tangent of x,
defined mathematically as
sinh (x) / cosh (x)
.
They may signal overflow if x is too large.
There are counterparts for the hyperbolic functions which take
complex arguments.
 Function: complex double csinh (complex double z)

 Function: complex float csinhf (complex float z)

 Function: complex long double csinhl (complex long double z)
 These functions return the complex hyperbolic sine of z, defined
mathematically as
(exp (z)  exp (z)) / 2
.
 Function: complex double ccosh (complex double z)

 Function: complex float ccoshf (complex float z)

 Function: complex long double ccoshl (complex long double z)
 These functions return the complex hyperbolic cosine of z, defined
mathematically as
(exp (z) + exp (z)) / 2
.
 Function: complex double ctanh (complex double z)

 Function: complex float ctanhf (complex float z)

 Function: complex long double ctanhl (complex long double z)
 These functions return the complex hyperbolic tangent of z,
defined mathematically as
csinh (z) / ccosh (z)
.
 Function: double asinh (double x)

 Function: float asinhf (float x)

 Function: long double asinhl (long double x)
 These functions return the inverse hyperbolic sine of xthe
value whose hyperbolic sine is x.
 Function: double acosh (double x)

 Function: float acoshf (float x)

 Function: long double acoshl (long double x)
 These functions return the inverse hyperbolic cosine of xthe
value whose hyperbolic cosine is x. If x is less than
1
, acosh
signals a domain error.
 Function: double atanh (double x)

 Function: float atanhf (float x)

 Function: long double atanhl (long double x)
 These functions return the inverse hyperbolic tangent of xthe
value whose hyperbolic tangent is x. If the absolute value of
x is greater than
1
, atanh
signals a domain error;
if it is equal to 1, atanh
returns infinity.
 Function: complex double casinh (complex double z)

 Function: complex float casinhf (complex float z)

 Function: complex long double casinhl (complex long double z)
 These functions return the inverse complex hyperbolic sine of
zthe value whose complex hyperbolic sine is z.
 Function: complex double cacosh (complex double z)

 Function: complex float cacoshf (complex float z)

 Function: complex long double cacoshl (complex long double z)
 These functions return the inverse complex hyperbolic cosine of
zthe value whose complex hyperbolic cosine is z. Unlike
the realvalued functions, there are no restrictions on the value of z.
 Function: complex double catanh (complex double z)

 Function: complex float catanhf (complex float z)

 Function: complex long double catanhl (complex long double z)
 These functions return the inverse complex hyperbolic tangent of
zthe value whose complex hyperbolic tangent is z. Unlike
the realvalued functions, there are no restrictions on the value of
z.