asin
description
Syntax
DOUBLE asin(DOUBLE x)
返回x的反正弦值，若 x不在-1到 1的范围之内，则返回 NULL.
example
mysql> select asin(0.5);
+---------------------+
| asin(0.5) |
+---------------------+
| 0.52359877559829893 |
+---------------------+
mysql> select asin(2);
+-----------+
| asin(2.0) |
+-----------+
| nan |
+-----------+keywords
ASIN