Syntax
ACOS(X)
Purpose
You can call this function to return the arc cosine of X. If the value of X is outside the range of [-1,1], the function returns NULL.
Examples
obclient> SELECT ACOS(-10), ACOS(0), ACOS(10), ACOS(-0.5), ACOS(0.5);
+-----------+--------------------+----------+--------------------+--------------------+
ACOS(-10) ACOS(0) ACOS(10) ACOS(-0.5) ACOS(0.5)
+-----------+--------------------+----------+--------------------+--------------------+
NULL 1.5707963267948966 NULL 2.0943951023931957 1.0471975511965979
+-----------+--------------------+----------+--------------------+--------------------+
1 row in set (0.00 sec)