From dfe0b2326b9700f5f5f5af566488dfe913348ab9 Mon Sep 17 00:00:00 2001
From: Mark Dickinson <dickinsm@gmail.com>
Date: Sun, 11 Jan 2015 13:08:05 +0000
Subject: [PATCH] Issue #21902: Replace incorrect 'hyperbolic arc sine' (etc.)
 with 'inverse hyperbolic sine' (etc.).  Remove meaningless reference to
 radians.

---
 Doc/library/cmath.rst | 8 ++++----
 Modules/cmathmodule.c | 6 +++---
 Modules/mathmodule.c  | 6 +++---
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/Doc/library/cmath.rst b/Doc/library/cmath.rst
index d7778df3173..a981d94a11b 100644
--- a/Doc/library/cmath.rst
+++ b/Doc/library/cmath.rst
@@ -149,13 +149,13 @@ Hyperbolic functions
 
 .. function:: acosh(x)
 
-   Return the hyperbolic arc cosine of *x*. There is one branch cut, extending left
-   from 1 along the real axis to -∞, continuous from above.
+   Return the inverse hyperbolic cosine of *x*. There is one branch cut,
+   extending left from 1 along the real axis to -∞, continuous from above.
 
 
 .. function:: asinh(x)
 
-   Return the hyperbolic arc sine of *x*. There are two branch cuts:
+   Return the inverse hyperbolic sine of *x*. There are two branch cuts:
    One extends from ``1j`` along the imaginary axis to ``∞j``,
    continuous from the right.  The other extends from ``-1j`` along
    the imaginary axis to ``-∞j``, continuous from the left.
@@ -163,7 +163,7 @@ Hyperbolic functions
 
 .. function:: atanh(x)
 
-   Return the hyperbolic arc tangent of *x*. There are two branch cuts: One
+   Return the inverse hyperbolic tangent of *x*. There are two branch cuts: One
    extends from ``1`` along the real axis to ``∞``, continuous from below. The
    other extends from ``-1`` along the real axis to ``-∞``, continuous from
    above.
diff --git a/Modules/cmathmodule.c b/Modules/cmathmodule.c
index 91b369a2f54..eb2853cedd2 100644
--- a/Modules/cmathmodule.c
+++ b/Modules/cmathmodule.c
@@ -192,7 +192,7 @@ c_acosh(Py_complex z)
 PyDoc_STRVAR(c_acosh_doc,
 "acosh(x)\n"
 "\n"
-"Return the hyperbolic arccosine of x.");
+"Return the inverse hyperbolic cosine of x.");
 
 
 static Py_complex
@@ -249,7 +249,7 @@ c_asinh(Py_complex z)
 PyDoc_STRVAR(c_asinh_doc,
 "asinh(x)\n"
 "\n"
-"Return the hyperbolic arc sine of x.");
+"Return the inverse hyperbolic sine of x.");
 
 
 static Py_complex
@@ -353,7 +353,7 @@ c_atanh(Py_complex z)
 PyDoc_STRVAR(c_atanh_doc,
 "atanh(x)\n"
 "\n"
-"Return the hyperbolic arc tangent of x.");
+"Return the inverse hyperbolic tangent of x.");
 
 
 static Py_complex
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 7f094ffb537..910d5ea57de 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -873,18 +873,18 @@ math_2(PyObject *args, double (*func) (double, double), char *funcname)
 FUNC1(acos, acos, 0,
       "acos(x)\n\nReturn the arc cosine (measured in radians) of x.")
 FUNC1(acosh, m_acosh, 0,
-      "acosh(x)\n\nReturn the hyperbolic arc cosine (measured in radians) of x.")
+      "acosh(x)\n\nReturn the inverse hyperbolic cosine of x.")
 FUNC1(asin, asin, 0,
       "asin(x)\n\nReturn the arc sine (measured in radians) of x.")
 FUNC1(asinh, m_asinh, 0,
-      "asinh(x)\n\nReturn the hyperbolic arc sine (measured in radians) of x.")
+      "asinh(x)\n\nReturn the inverse hyperbolic sine of x.")
 FUNC1(atan, atan, 0,
       "atan(x)\n\nReturn the arc tangent (measured in radians) of x.")
 FUNC2(atan2, m_atan2,
       "atan2(y, x)\n\nReturn the arc tangent (measured in radians) of y/x.\n"
       "Unlike atan(y/x), the signs of both x and y are considered.")
 FUNC1(atanh, m_atanh, 0,
-      "atanh(x)\n\nReturn the hyperbolic arc tangent (measured in radians) of x.")
+      "atanh(x)\n\nReturn the inverse hyperbolic tangent of x.")
 
 static PyObject * math_ceil(PyObject *self, PyObject *number) {
     _Py_IDENTIFIER(__ceil__);