The GNU C Library - Hyperbolic Functions

Hyperbolic Functions

The functions in this section are related to the exponential functions; see Exponents and Logarithms.

Function double sinh (double x)

The sinh function returns the hyperbolic sine of x, defined mathematically as exp (x) - exp (-x) / 2 . The function fails, and sets errno to ERANGE , if the value of x is too large; that is, if overflow occurs.

Function double cosh (double x)

The cosh function returns the hyperbolic cosine of x, defined mathematically as exp (x) + exp (-x) / 2 . The function fails, and sets errno to ERANGE , if the value of x is too large; that is, if overflow occurs.

Function double tanh (double x)

This function returns the hyperbolic tangent of x, whose mathematical definition is sinh (x) / cosh (x) .

Function double asinh (double x)

This function returns the inverse hyperbolic sine of x---the value whose hyperbolic sine is x.

Function double acosh (double x)

This function returns the inverse hyperbolic cosine of x---the value whose hyperbolic cosine is x. If x is less than 1 , acosh returns HUGE_VAL .

Function double atanh (double x)

This function returns the inverse hyperbolic tangent of x---the value whose hyperbolic tangent is x. If the absolute value of x is greater than or equal to 1 , atanh returns HUGE_VAL .