# Math.Tan(Double) Method

## Definition

Important

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Returns the tangent of the specified angle.

```
public:
static double Tan(double a);
```

`public static double Tan (double a);`

`static member Tan : double -> double`

`Public Shared Function Tan (a As Double) As Double`

#### Parameters

- a
- Double

An angle, measured in radians.

#### Returns

The tangent of `a`

. If `a`

is equal to NaN, NegativeInfinity, or PositiveInfinity, this method returns NaN.

## Examples

The following example demonstrates how to calculate the tangent of an angle and display it to the console.

```
// This example demonstrates Math.Atan()
// Math.Atan2()
// Math.Tan()
using namespace System;
int main()
{
double x = 1.0;
double y = 2.0;
double angle;
double radians;
double result;
// Calculate the tangent of 30 degrees.
angle = 30;
radians = angle * (Math::PI / 180);
result = Math::Tan( radians );
Console::WriteLine( "The tangent of 30 degrees is {0}.", result );
// Calculate the arctangent of the previous tangent.
radians = Math::Atan( result );
angle = radians * (180 / Math::PI);
Console::WriteLine( "The previous tangent is equivalent to {0} degrees.", angle );
// Calculate the arctangent of an angle.
String^ line1 = "{0}The arctangent of the angle formed by the x-axis and ";
String^ line2 = "a vector to point ({0},{1}) is {2}, ";
String^ line3 = "which is equivalent to {0} degrees.";
radians = Math::Atan2( y, x );
angle = radians * (180 / Math::PI);
Console::WriteLine( line1, Environment::NewLine );
Console::WriteLine( line2, x, y, radians );
Console::WriteLine( line3, angle );
}
/*
This example produces the following results:
The tangent of 30 degrees is 0.577350269189626.
The previous tangent is equivalent to 30 degrees.
The arctangent of the angle formed by the x-axis and
a vector to point (1,2) is 1.10714871779409,
which is equivalent to 63.434948822922 degrees.
*/
```

```
// This example demonstrates Math.Atan()
// Math.Atan2()
// Math.Tan()
using System;
class Sample
{
public static void Main()
{
double x = 1.0;
double y = 2.0;
double angle;
double radians;
double result;
// Calculate the tangent of 30 degrees.
angle = 30;
radians = angle * (Math.PI/180);
result = Math.Tan(radians);
Console.WriteLine("The tangent of 30 degrees is {0}.", result);
// Calculate the arctangent of the previous tangent.
radians = Math.Atan(result);
angle = radians * (180/Math.PI);
Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle);
// Calculate the arctangent of an angle.
String line1 = "{0}The arctangent of the angle formed by the x-axis and ";
String line2 = "a vector to point ({0},{1}) is {2}, ";
String line3 = "which is equivalent to {0} degrees.";
radians = Math.Atan2(y, x);
angle = radians * (180/Math.PI);
Console.WriteLine(line1, Environment.NewLine);
Console.WriteLine(line2, x, y, radians);
Console.WriteLine(line3, angle);
}
}
/*
This example produces the following results:
The tangent of 30 degrees is 0.577350269189626.
The previous tangent is equivalent to 30 degrees.
The arctangent of the angle formed by the x-axis and
a vector to point (1,2) is 1.10714871779409,
which is equivalent to 63.434948822922 degrees.
*/
```

```
// This example demonstrates Math.Atan()
// Math.Atan2()
// Math.Tan()
// Functions 'atan', 'atan2', and 'tan' may be used instead.
open System
[<EntryPoint>]
let main _ =
let x = 1.
let y = 2.
// Calculate the tangent of 30 degrees.
let angle = 30.
let radians = angle * (Math.PI / 180.)
let result = Math.Tan radians
printfn $"The tangent of 30 degrees is {result}."
// Calculate the arctangent of the previous tangent.
let radians = Math.Atan result
let angle = radians * (180. / Math.PI)
printfn $"The previous tangent is equivalent to {angle} degrees."
// Calculate the arctangent of an angle.
let radians = Math.Atan2(y, x)
let angle = radians * (180. / Math.PI)
printfn
$"""The arctangent of the angle formed by the x-axis and
a vector to point ({x},{y}) is {radians},
which is equivalent to {angle} degrees."""
0
//This example produces the following results:
// The tangent of 30 degrees is 0.577350269189626.
// The previous tangent is equivalent to 30 degrees.
//
// The arctangent of the angle formed by the x-axis and
// a vector to point (1,2) is 1.10714871779409,
// which is equivalent to 63.434948822922 degrees.
```

```
' This example demonstrates Math.Atan()
' Math.Atan2()
' Math.Tan()
Class Sample
Public Shared Sub Main()
Dim x As Double = 1.0
Dim y As Double = 2.0
Dim angle As Double
Dim radians As Double
Dim result As Double
' Calculate the tangent of 30 degrees.
angle = 30
radians = angle *(Math.PI / 180)
result = Math.Tan(radians)
Console.WriteLine("The tangent of 30 degrees is {0}.", result)
' Calculate the arctangent of the previous tangent.
radians = Math.Atan(result)
angle = radians *(180 / Math.PI)
Console.WriteLine("The previous tangent is equivalent to {0} degrees.", angle)
' Calculate the arctangent of an angle.
Dim line1 As [String] = "{0}The arctangent of the angle formed by the x-axis and "
Dim line2 As [String] = "a vector to point ({0},{1}) is {2}, "
Dim line3 As [String] = "which is equivalent to {0} degrees."
radians = Math.Atan2(y, x)
angle = radians *(180 / Math.PI)
Console.WriteLine(line1, Environment.NewLine)
Console.WriteLine(line2, x, y, radians)
Console.WriteLine(line3, angle)
End Sub
End Class
'
'This example produces the following results:
'
'The tangent of 30 degrees is 0.577350269189626.
'The previous tangent is equivalent to 30 degrees.
'
'The arctangent of the angle formed by the x-axis and
'a vector to point (1,2) is 1.10714871779409,
'which is equivalent to 63.434948822922 degrees.
'
```

## Remarks

The angle, `a`

, must be in radians. Multiply by Math.PI/180 to convert degrees to radians.

This method calls into the underlying C runtime, and the exact result or valid input range may differ between different operating systems or architectures.