bpo-37548: Document range of atan, acos and asin (GH-14717)
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index bfce41a..be953cf 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -366,17 +366,20 @@
.. function:: acos(x)
- Return the arc cosine of *x*, in radians.
+ Return the arc cosine of *x*, in radians. The result is between ``0`` and
+ ``pi``.
.. function:: asin(x)
- Return the arc sine of *x*, in radians.
+ Return the arc sine of *x*, in radians. The result is between ``-pi/2`` and
+ ``pi/2``.
.. function:: atan(x)
- Return the arc tangent of *x*, in radians.
+ Return the arc tangent of *x*, in radians. The result is between ``-pi/2`` and
+ ``pi/2``.
.. function:: atan2(y, x)
diff --git a/Misc/ACKS b/Misc/ACKS
index c011999..31f8dda 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -251,6 +251,7 @@
Arnaud Calmettes
Daniel Calvelo
Tony Campbell
+Giovanni Cappellotto
Brett Cannon
Tristan Carel
Mike Carlton
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 552cb78..92c40b3 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1072,19 +1072,22 @@
FUNC1(acos, acos, 0,
"acos($module, x, /)\n--\n\n"
- "Return the arc cosine (measured in radians) of x.")
+ "Return the arc cosine (measured in radians) of x.\n\n"
+ "The result is between 0 and pi.")
FUNC1(acosh, m_acosh, 0,
"acosh($module, x, /)\n--\n\n"
"Return the inverse hyperbolic cosine of x.")
FUNC1(asin, asin, 0,
"asin($module, x, /)\n--\n\n"
- "Return the arc sine (measured in radians) of x.")
+ "Return the arc sine (measured in radians) of x.\n\n"
+ "The result is between -pi/2 and pi/2.")
FUNC1(asinh, m_asinh, 0,
"asinh($module, x, /)\n--\n\n"
"Return the inverse hyperbolic sine of x.")
FUNC1(atan, atan, 0,
"atan($module, x, /)\n--\n\n"
- "Return the arc tangent (measured in radians) of x.")
+ "Return the arc tangent (measured in radians) of x.\n\n"
+ "The result is between -pi/2 and pi/2.")
FUNC2(atan2, m_atan2,
"atan2($module, y, x, /)\n--\n\n"
"Return the arc tangent (measured in radians) of y/x.\n\n"