SQL Server COS() Function

COS() is a mathematical function in SQL Server used to calculate the cosine value of a given angle. The function accepts an angle value as a parameter and returns its cosine value.

Syntax

COS(angle)

The parameter angle is the angle value in radians for which you want to calculate the cosine value.

Usage

The COS() function is commonly used for calculating trigonometric functions such as the cosine value of an angle. In mathematics and engineering, it is often necessary to calculate trigonometric functions to solve various problems such as finding the distance and angle between two objects.

Examples

Here are two examples of using the COS() function.

Example 1

Suppose there is a right triangle with an angle of 45 degrees and a hypotenuse of 10. Now, we need to calculate the length of the base of the triangle. We can use the following query to calculate the length of the base:

DECLARE @angle FLOAT = 45
DECLARE @hypotenuse FLOAT = 10

SELECT @hypotenuse * COS(@angle * PI() / 180) AS adjacent

The output is:

Therefore, the length of the base of the triangle is 7.0710678.

Example 2

Suppose there is a table employee that contains the ID, name, and monthly salary of employees. Now, we need to calculate the gross salary and net salary of each employee, where the net salary is the gross salary minus 20% personal income tax. We can use the following query to calculate this:

SELECT id, name, salary, salary * 0.8 AS net_salary
FROM employee

The output is:

Therefore, we have calculated the gross and net salaries of each employee.

Conclusion

The COS() function is a mathematical function in SQL Server used to calculate the cosine value of a given angle. It is commonly used for calculating trigonometric functions such as finding the distance and angle between two objects. Through the examples, we can see how to use the function in practical applications to solve various problems.