ACOSH(X) (Fortran 2008)

Purpose

Inverse hyperbolic cosine function.

Class

Elemental function

Argument type and attributes

X
must be of type real or type complex.

Result type and attributes

Same as X.

Result value

The result value approximates the inverse hyperbolic cosine of X.

If X is of type complex, the imaginary part of the result value is as follows:
  • It is expressed in radians.
  • It is in the range 0 ≤ AIMAG(ACOSH(X)) ≤ PI.

Examples

ACOSH(1.5430806) has the value 1.0, approximately.

ACOSH((1.5430806, 0.000000)) has the value (1.000000, 0.000000), approximately.