MySQL - ACOS() Function
ACOS() function of MySQL is used to calculate the arc cosine value of numerical data in the database tables.
Arc cosine function is a part of trigonometry and is defined as the inverse of the cosine function. In simple words, in a right-angled triangle, cosine function is defined as the ratio of an adjacent side of a non-right angle to the hypotenuse; but the arc cosine function is defined as its inverse, where the domain of cosine function becomes the range of arc cosine function and vice-versa.
This function accepts an integer number as an argument and returns the arc cosine value for the given integer.
Syntax
Following is the syntax of MySQL ACOS() function −
ACOS(x)
Parameters
This function takes an integer value between 1 and -1 representing a cosine as a parameter.
Return Value
This function returns the angle in radians of the given cosine value.
Example
The query calculates the arccosine of 0.8 (cosine inverse of 0.8) −
SELECT ACOS(0.8) As Result;
Output
This will produce the following result −
| Result |
|---|
| 0.6435011087932843 |
Example
You can also pass negative value to this function as shown below −
SELECT ACOS(-0.5) As Result;
Output
This will produce the following result −
| Result |
|---|
| 2.0943951023931957 |
Example
If the value passed is to this function is not in the range of -1 to 1 this function returns a NULL value −
SELECT ACOS(6) As Result;
Output
This will produce the following result −
| Result |
|---|
| NULL |
Example
This query calculates the arccosine (inverse cosine) of the value 1 and returns the result. In this case, it will return the value 0, which is the arccosine of 1.
SELECT ACOS(1) As Result;
Output
This will produce the following result −
| Result |
|---|
| 0 |