Issue #21902: Replace incorrect 'hyperbolic arc sine' (etc.) with 'inverse hyperbolic sine' (etc.). Remove meaningless reference to radians.
diff --git a/Doc/library/cmath.rst b/Doc/library/cmath.rst
index 5cbb426..0a05686 100644
--- a/Doc/library/cmath.rst
+++ b/Doc/library/cmath.rst
@@ -161,13 +161,13 @@
.. 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.
@@ -178,7 +178,7 @@
.. 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.