.. Copyright 1988-2021 Free Software Foundation, Inc. This is part of the GCC manual. For copying conditions, see the GPL license file .. _cosh: COSH --- Hyperbolic cosine function *********************************** .. index:: COSH .. index:: DCOSH .. index:: hyperbolic cosine .. index:: hyperbolic function, cosine .. index:: cosine, hyperbolic .. function:: COSH(X) ``COSH(X)`` computes the hyperbolic cosine of :samp:`{X}`. :param X: The type shall be ``REAL`` or ``COMPLEX``. :return: The return value has same type and kind as :samp:`{X}`. If :samp:`{X}` is complex, the imaginary part of the result is in radians. If :samp:`{X}` is ``REAL``, the return value has a lower bound of one, \cosh (x) \geq 1. :samp:`{Standard}:` Fortran 77 and later, for a complex argument Fortran 2008 or later :samp:`{Class}:` Elemental function :samp:`{Syntax}:` .. code-block:: fortran X = COSH(X) :samp:`{Example}:` .. code-block:: fortran program test_cosh real(8) :: x = 1.0_8 x = cosh(x) end program test_cosh :samp:`{Specific names}:` ============ ============= =========== ==================== Name Argument Return type Standard ============ ============= =========== ==================== ``COSH(X)`` ``REAL(4) X`` ``REAL(4)`` Fortran 77 and later ``DCOSH(X)`` ``REAL(8) X`` ``REAL(8)`` Fortran 77 and later ============ ============= =========== ==================== :samp:`{See also}:` Inverse function: ACOSH