# Python tan: How to Calculate Tangent in Python

Some of the most essential mathematical methods in Python are defined in the math module. These include trigonometric functions, representation functions, logarithmic functions, angle conversion functions, etc. Let’s discuss how to calculate tangent.

## Python tan

Python tan() is a built-in math module function used to find the tan value of the parameter passed in radians. If x is passed as a parameter in the tan() function (tan(x)), it returns the tan value of x in radians.

We can use a math module by importing it. The syntax would be import math.

After importing, we call the tan() function using the static object.

### Syntax

`math.tan(var)`

Here var is the variable of which tan we have to find.

### Parameters

The tan() function takes one parameter var, which takes values of numeric datatype and throws TypeError if an argument is of any other data type is passed.

### Return Value

It returns the tan value of the number in the float datatype.

See the following example.

```import math

var = 0.36
print(math.tan(var))
```

### Example programs on tan() method in Python

#### Example 1: Write a program to show the working of a tan() method in Python.

```import math

a1 = 0.36
b1 = 1
c1 = -1
d1 = -0.36

print("Value for parameter ", a1, " is ", math.tan(a1))
print("Value for parameter ", b1, " is ", math.tan(b1))
print("Value for parameter ", c1, " is ", math.tan(c1))
print("Value for parameter ", d1, " is ", math.tan(d1))
```

#### Output

```Value for parameter  0.36  is  0.3764028516420269
Value for parameter  1  is  1.5574077246549023
Value for parameter  -1  is  -1.5574077246549023
Value for parameter  -0.36  is  -0.3764028516420269
```

In this example, we have seen that by passing a valid parameter which is different for different examples, we get the desired tan() method solution.

#### Example 2: Write a program to pass the value out of range from the tan() function and display the output.

```import math

x = "H"
print(math.tan(x))
```

#### Output

```TypeError: must be real number, not str
```

In this example, we passed a value that was not real, so this program threw an error stating that the number must be real.

See the third example.

```# app.py

import math

a = math.pi / 6

# returning the value of tangent of pi / 6
print("The value of tangent of pi / 6 is : ", math.tan(a))
```

#### Output

```python3 app.py
The value of tangent of pi / 6 is :  0.5773502691896256```