# ACOS function in Oracle

ACOS is one of the vital Numeric/Math functions of Oracle. It is used to get the arc cosine of a number. The ACOS function is supported in the various versions of the Oracle/PLSQL, including, Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i and Oracle 8i.

Syntax:

ACOS ( number )


Parameters:
number: It is used to specify the number to get the arc cosine value of.

Example 1:

ACOS (1)

Output:

0


Explanation:
The Arc Cosine means the inverse of the cosine. The arc cosine value of 1 is 0 radian, and so is the result.

Example 2:

ACOS (0.5)

Output:

1.04719755


Explanation:
The Arc Cosine means the inverse of the cosine. The arc cosine value of 0.5 is 60 degrees i.e, 1.04719755 radians, and so is the result.

Example 3:

ACOS (-0.5)

Output:

2.0943951


Explanation:
The Arc Cosine means the inverse of the cosine. The arc cosine value of -0.5 is 120 degrees i.e, 2.094395 radians, and so is the result.