SQL Server ACOS() Function

SQL Server ACOS() Function

The SQL Server ACOS() function returns the arccosine, or inverse cosine, of a specified number. The result is expressed in radians and is useful in trigonometric calculations.

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Syntax

SELECT ACOS(number);

The ACOS() function takes a single argument:

• number: The numeric expression for which to find the arccosine. The value must be between -1 and 1.

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Example SQL Server ACOS() Function Queries

Let's look at some examples of SQL Server ACOS() function queries:

1. Basic ACOS() Example

SELECT ACOS(1) AS result;

This query returns the arccosine of 1. The result will be:

result
------
0

2. ACOS() with a Negative Value

SELECT ACOS(-1) AS result;

This query returns the arccosine of -1. The result will be:

result
------
3.141592653589793

3. ACOS() with a Column

SELECT angle_value, ACOS(angle_value) AS acos_value
FROM angles;

This query returns the arccosine of the angle_value column for each record in the angles table. The result will show the original angle_value and its corresponding arccosine as acos_value.

4. ACOS() with a Variable

DECLARE @myValue FLOAT;
SET @myValue = 0.5;
SELECT ACOS(@myValue) AS result;

This query uses a variable to store a numeric value and then returns its arccosine. The result will be:

result
------
1.0471975511965979

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Full Example

Let's go through a complete example that includes creating a table, inserting data, and using the ACOS() function.

Step 1: Creating a Table

This step involves creating a new table named example_table to store some sample data.

CREATE TABLE example_table (
    id INT PRIMARY KEY,
    angle_value FLOAT
);

In this example, we create a table named example_table with columns for id and angle_value.

Step 2: Inserting Data into the Table

This step involves inserting some sample data into the example_table.

INSERT INTO example_table (id, angle_value) VALUES (1, 1);
INSERT INTO example_table (id, angle_value) VALUES (2, 0.5);
INSERT INTO example_table (id, angle_value) VALUES (3, -0.5);
INSERT INTO example_table (id, angle_value) VALUES (4, -1);

Here, we insert data into the example_table.

Step 3: Using the ACOS() Function

This step involves using the ACOS() function to return the arccosine of the angle_value column.

SELECT id, angle_value, ACOS(angle_value) AS acos_value
FROM example_table;

This query retrieves the id, angle_value, and the arccosine of the angle_value column for each row in the example_table. The result will be:

id  angle_value  acos_value
--- ------------ -----------
1   1            0
2   0.5          1.0471975511965979
3   -0.5         2.0943951023931957
4   -1           3.141592653589793

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Conclusion

The SQL Server ACOS() function is a powerful tool for returning the arccosine, or inverse cosine, of a specified number. Understanding how to use the ACOS() function and its syntax is essential for effective trigonometric calculations and data processing in SQL Server.