acos

This function is used to return the arc cosine value of a given angle a.

Syntax

acos(DOUBLE a)

Parameters

Table 1 Parameter

Parameter

Mandatory

Type

Description

a

Yes

DOUBLE, BIGINT, DECIMAL, or STRING

The value range is [-1,1]. The value can be a float, integer, or string.

If the value is not of the DOUBLE type, the system will implicitly convert it to the DOUBLE type for calculation.

Return Values

The return value is of the DOUBLE type. The value ranges from 0 to Pi.

Note

  • If the value of a is not within the range [-1,1], NaN is returned.

  • If the value of a is NULL, NULL is returned.

Example Code

The value 3.141592653589793 is returned.

select acos(-1);

The value 0 is returned.

select acos(1);

The value NULL is returned.

select acos(null);

The value NAN is returned.

select acos(10);