类别：: 数值函数（三角函数）

COS¶

计算其实参的余弦值；实参应以弧度表示。

语法¶

COS( <input_expr> )

实参¶

input_expr: The value or expression to operate on. The value must be in radians, not degrees. The data type must be FLOAT.

返回¶

This function returns a value of type FLOAT.

示例¶

SELECT COS(0), COS(PI()/3), COS(RADIANS(90));

+--------+-------------+------------------+
| COS(0) | COS(PI()/3) | COS(RADIANS(90)) |
|--------+-------------+------------------|
|      1 |         0.5 |  6.123233996e-17 |
+--------+-------------+------------------+