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跳到主要内容

ACOS

acos

description

Syntax

DOUBLE acos(DOUBLE x) 返回x的反余弦值,若 x不在-11的范围之内,则返回 nan.

example

mysql> select acos(1);
+-----------+
| acos(1.0) |
+-----------+
| 0 |
+-----------+
mysql> select acos(0);
+--------------------+
| acos(0.0) |
+--------------------+
| 1.5707963267948966 |
+--------------------+
mysql> select acos(-2);
+------------+
| acos(-2.0) |
+------------+
| nan |
+------------+

keywords

ACOS