(Math Functions): asin, acos, log, log10 report domain-error errors.

1 files changed, 9 insertions, 8 deletions

diff --git a/lispref/numbers.texi b/lispref/numbers.texi
index 63f3035dfc..9c71922c0d 100644
--- a/lispref/numbers.texi
+++ b/lispref/numbers.texi
@@ -1047,8 +1047,8 @@ pi/2
 @tex
 @math{\pi/2}
 @end tex
-(inclusive) whose sine is @var{arg}; if, however, @var{arg}
-is out of range (outside [-1, 1]), then the result is a NaN.
+(inclusive) whose sine is @var{arg}; if, however, @var{arg} is out of
+range (outside [-1, 1]), it signals a @code{domain-error} error.
 @end defun
 
 @defun acos arg
@@ -1059,8 +1059,8 @@ pi
 @tex
 @math{\pi}
 @end tex
-(inclusive) whose cosine is @var{arg}; if, however, @var{arg}
-is out of range (outside [-1, 1]), then the result is a NaN.
+(inclusive) whose cosine is @var{arg}; if, however, @var{arg} is out
+of range (outside [-1, 1]), it signals a @code{domain-error} error.
 @end defun
 
 @defun atan y &optional x
@@ -1112,8 +1112,8 @@ If you don't specify @var{base}, the base
 @ifnottex
 @i{e}
 @end ifnottex
-is used.  If @var{arg}
-is negative, the result is a NaN.
+is used.  If @var{arg} is negative, it signals a @code{domain-error}
+error.
 @end defun
 
 @ignore
@@ -1132,8 +1132,9 @@ lose accuracy.
 
 @defun log10 arg
 This function returns the logarithm of @var{arg}, with base 10.  If
-@var{arg} is negative, the result is a NaN.  @code{(log10 @var{x})}
-@equiv{} @code{(log @var{x} 10)}, at least approximately.
+@var{arg} is negative, it signals a @code{domain-error} error.
+@code{(log10 @var{x})} @equiv{} @code{(log @var{x} 10)}, at least
+approximately.
 @end defun
 
 @defun expt x y