In the previous article, we have discussed Python Program for asin() Function

**atan() Function in Python:**

The arc tangent of a number (x) is returned as a numeric value between -PI/2 and PI/2 radians by the math.atan() method.

Arc tangent is also defined as an inverse tangent function of x, where x is the value to be calculated for the arc tangent.

**Syntax:**

math.atan(x)

**Parameters:**

**x: **This is Required. It is a number that is either positive or negative. If x is not a number, TypeError is returned.

**Return Value:**

It returns a float value ranging from -PI/2 to PI/2 representing a number’s arc tangent.

The Arc Tangent value is returned if the number argument is positive or negative.

The atan() function throws a TypeError if the number argument is not a number.

**Examples:**

**Example1:**

**Input:**

Given first number = 0.7 Given second number = 1

**Output:**

The result after applying atan() function on above given first number 0.7 = 0.6107259643892086 The result after applying atan() function on above given second number 1 = 0.7853981633974483

**Example2:**

**Input:**

Given first number = -1 Given second number = 0.3

**Output:**

The result after applying atan() function on above given first number -1 = -0.7853981633974483 The result after applying atan() function on above given second number 0.3 = 0.2914567944778671

## Program for atan() Function in Python

### Method #1: Using Built-in Functions (Static Input)

**Approach:**

- Import math module using the import keyword.
- Give the list as static input and store it in a variable.
- Give the first number as static input and store it in another variable.
- Apply math.atan() function to the given first number to get the arc tangent value (inverse of tangent ) of a given number.
- Store it in another variable.
- Print the above result.
- Similarly, do the same for the other number.
- Apply math.atan() function to the given list element and print it.
- The Exit of Program.

**Below is the implementation:**

# Import math module using the import keyword. import math # Give the list as static input and store it in a variable. gvn_lst = [0.6, -0.3, 1, 0.8] # Give the first number as static input and store it in another variable. gvn_numb1 = 0.7 # Apply math.atan() function to the given first number to get arc tangent value # (inverse of tangent) of a given number. # Store it in another variable. fnl_rslt = math.atan(gvn_numb1) print("The result after applying atan() function on above given first number", gvn_numb1, " = ", fnl_rslt) # similarly do the same for the other number. gvn_numb2 = 1 print("The result after applying atan() function on above given second number", gvn_numb2, " = ", math.atan(gvn_numb2)) # Apply math.atan() function to the given list element and print it. print( "The result after applying atan() function on given list element gvnlst[1] = ", math.atan(gvn_lst[1]))

**Output:**

The result after applying atan() function on above given first number 0.7 = 0.6107259643892086 The result after applying atan() function on above given second number 1 = 0.7853981633974483 The result after applying atan() function on given list element gvnlst[1] = -0.2914567944778671

### Method #2: Using Built-in Functions (User Input)

**Approach:**

- Import math module using the import keyword.
- Give the list as user input using list(),map(),input(),and split() functions.
- Store it in a variable.
- Give the first number as user input using the float(input()) function and store it in a variable.
- Apply math.atan() function to the given first number to get the arc tangent value (inverse of tangent ) of a given number.
- Store it in another variable.
- Print the above result.
- Similarly, do the same for the other number.
- Apply math.atan() function to the given list element and print it.
- The Exit of Program.

**Below is the implementation:**

# Import math module using the import keyword. import math # Give the list as user input using list(),map(),input(),and split() functions. # Store it in a variable. gvn_lst = list(map(float, input( 'Enter some random List Elements separated by spaces = ').split())) # Give the first number as user input using the float(input()) function # and store it in a variable. gvn_numb1 = float(input("Enter some random number = ")) # Apply math.atan() function to the given first number to get arc tangent value # (inverse of tangent) of a given number. # Store it in another variable. fnl_rslt = math.atan(gvn_numb1) print("The result after applying atan() function on above given first number", gvn_numb1, " = ", fnl_rslt) # similarly do the same for the other number. gvn_numb2 = float(input("Enter some random number = ")) print("The result after applying atan() function on above given second number", gvn_numb2, " = ", math.atan(gvn_numb2)) # Apply math.atan() function to the given list element and print it. print( "The result after applying atan() function on given list element gvnlst[2] = ", math.atan(gvn_lst[2]))

**Output:**

Enter some random List Elements separated by spaces = 0 2 0.9 1 -3 Enter some random number = -1 The result after applying atan() function on above given first number -1.0 = -0.7853981633974483 Enter some random number = 0.3 The result after applying atan() function on above given second number 0.3 = 0.2914567944778671 The result after applying atan() function on given list element gvnlst[2] = 0.7328151017865066

Know all about Mathematical Functions in Python by going through our Python Mathematical Methods Examples well explained step by step.