MySQL COS() Function

 The COS() function in MySQL is used to calculate the cosine of a number. The argument passed to COS() should be in radians (not degrees), and the result will be a value between -1 and 1.

Syntax:

COS(number)

• number: This is the angle in radians for which the cosine is calculated.

Example 1: Basic usage

SELECT COS(0);  -- returns 1.0 because cos(0) = 1

Example 2: Cosine of a number in radians

SELECT COS(PI()/3);  -- returns 0.5 because cos(π/3) = 0.5

Example 3: Using COS() with a column value

Assume you have a table called angles with a column angle_in_radians:

SELECT angle_in_radians, COS(angle_in_radians) AS cosine_value
FROM angles;

This query will return the cosine of the angle_in_radians values stored in the angles table.

Important Notes:

• The argument to COS() must be in radians. If you have an angle in degrees, you need to first convert it to radians by multiplying the degree value by PI()/180.

  Example: Converting degrees to radians:

  SELECT COS(30 * PI() / 180);  -- This will return cos(30 degrees)
  

Trigonometric Functions in MySQL:

MySQL provides other trigonometric functions as well, such as:

• SIN() for sine,
• TAN() for tangent,
• ACOS() for arc cosine (inverse cosine),
• ASIN() for arc sine,
• ATAN() for arc tangent.

These functions all use radians as input and return results based on the corresponding trigonometric calculations.