COS

描述

计算参数的余弦值

语法

COS(<a>)

参数

参数	说明
<a>	浮点数，要计算参数的弧度值

返回值

参数 <a> 的余弦值，弧度制表示。

特殊情况

• 当 a 为 NaN，返回 NaN
• 当 a 为正无穷或负无穷（±Infinity），返回 NaN
• 当 a 为 NULL，返回 NULL

举例

select cos(1);

+---------------------+
| cos(1.0)            |
+---------------------+
| 0.54030230586813977 |
+---------------------+

select cos(0);

+------------------------+
| cos(cast(0 as DOUBLE)) |
+------------------------+
|                    1.0 |
+------------------------+

select cos(Pi());

+-----------+
| cos(pi()) |
+-----------+
|        -1 |
+-----------+

select cos(cast('nan' as double));

+----------------------------+
| cos(cast('nan' AS DOUBLE)) |
+----------------------------+
| NaN                        |
+----------------------------+

select cos(cast('inf' as double));

+----------------------------+
| cos(cast('inf' AS DOUBLE)) |
+----------------------------+
| NaN                        |
+----------------------------+

select cos(cast('-inf' as double));

+-----------------------------+
| cos(cast('-inf' AS DOUBLE)) |
+-----------------------------+
| NaN                         |
+-----------------------------+