# How the ACOS() function works in Mariadb?

The `ACOS()`

function in MariaDB is used to calculate the arc cosine of a number.

The `ACOS()`

function in MariaDB is used to calculate the arc cosine of a number. It returns the arc cosine of a number in radians, which is the inverse of the cosine function.

## Syntax

The syntax for the MariaDB `ACOS()`

function is as follows:

```
ACOS(number)
```

The `number`

parameter is a numeric value between -1 and 1 for which you want to find the arc cosine. The function returns the arc cosine of `number`

in radians.

## Examples

### Arc Cosine of 1

To find the arc cosine of 1:

```
SELECT ACOS(1);
```

`0`

The output is 0 radians, which is the arc cosine of 1.

### Arc Cosine of 0

This example calculates the arc cosine of 0:

```
SELECT ACOS(0);
```

`1.5707963267948966`

The output is approximately 1.57 radians, which is ( \frac{\pi}{2} ) radians, the arc cosine of 0.

### Arc Cosine of -1

To find the arc cosine of -1:

```
SELECT ACOS(-1);
```

`3.141592653589793`

The output is approximately 3.14 radians, which is ( \pi ) radians, the arc cosine of -1.

### Arc Cosine of a Decimal

Calculating the arc cosine of a decimal number:

```
SELECT ACOS(0.5);
```

`1.0471975511965979`

The output is approximately 1.05 radians, which is the arc cosine of 0.5.

### Arc Cosine in an Expression

Using `ACOS()`

in an expression with other functions:

```
SELECT ACOS(ROUND(COS(1), 2));
```

`1.0003592173949747`

The output is 1 radian, which is the arc cosine of the cosine of 1, rounded to two decimal places.

## Related Functions

Here are a few functions related to MariaDB’s `ACOS()`

:

- MariaDB
`COS()`

function is used to find the cosine of a number. - MariaDB
`ASIN()`

function calculates the arc sine of a number. - MariaDB
`ATAN()`

function finds the arc tangent of a number.

## Conclusion

The `ACOS()`

function is an important trigonometric function in MariaDB that allows you to find the arc cosine of a number, providing the angle in radians whose cosine is the given number. It is especially useful in geometric calculations and when working with angles in various mathematical and scientific applications. Understanding how to use `ACOS()`

effectively can be a valuable skill in database management and analysis.