In SQL Server, the TAN() function returns the tangent of the input expression.

You provide the value as an argument when calling the function.

Syntax

The syntax goes like this:

TAN ( float_expression ) 

Where float_expression is an expression of type float or of a type that can be implicitly converted to float, interpreted as number of radians.

Example 1 – Basic Usage

Here’s a basic example that returns the tangent of a single value.

SELECT TAN(1) Result;

Result:

+-----------------+
| Result          |
|-----------------|
| 1.5574077246549 |
+-----------------+

And with another value.

SELECT TAN(2.3) Result;

Result:

+-------------------+
| Result            |
|-------------------|
| -1.11921364173413 |
+-------------------+

Example 2 – Negative Value

Here we switch the previous value to negative value.

SELECT TAN(-2.3) Result;

Result:

+------------------+
| Result           |
|------------------|
| 1.11921364173413 |
+------------------+

Example 3 – Expressions

You can also pass in expressions like this:

SELECT TAN(2.5 + 0.3) Result;

Result:

+--------------------+
| Result             |
|--------------------|
| -0.355529831651176 |
+--------------------+

Example 4 – Passing in a Function

In this example I pass in the T-SQL PI() function as the argument.

SELECT 
  PI() 'PI',
  TAN(PI()) 'Tangent of PI';

Result:

+------------------+-----------------------+
| PI               | Tangent of PI         |
|------------------+-----------------------|
| 3.14159265358979 | -1.22464679914735E-16 |
+------------------+-----------------------+