…
►
§19.2(iv) A Related Function:
►Let
and
.
…Formulas involving
that are customarily different for circular cases, ordinary hyperbolic cases, and (hyperbolic) Cauchy principal values, are united in a single formula by using
.
…
►When
and
are positive,
is an inverse circular
function if
and an inverse hyperbolic
function (or logarithm) if
:
…For the special cases of
and
see (
19.6.15).
…