# math.atan2() method with example in Python

Python math.atan2() method: Here, we are going to learn about the math.atan2() method with example in Python.
Submitted by IncludeHelp, on April 21, 2019

## Python math.atan2() method

math.atan2() method is a library method of math module, it is used to get the arc tangent value of "y/x" (i.e. atan(y/x)), it accepts two numbers and returns arc tangent of "y/x".

Note: math.atan2() method accepts the only number, if we provide anything else except the number, it returns error TypeError - "TypeError: a float is required".

Syntax of math.atan2() method:

```    math.atan2(y, x)
```

Parameter(s): y, x – are the numbers whose arc tangent to be calculate (i.e. atan(y/x)).

Return value: float – it returns a float value that is the arc tangent value of the numbers y/x.

Example:

```    Input:
y = 0.2345
x = 1.234

# function call
print(math.atan2(y, x))

Output:
0.18779323183177443
```

### Python code to demonstrate example of math.atan2() method

```# python code to demonstrate example of
# math.atan2() method

# importing math module
import math

# numbers
x = -1
y = 1
print("atan2(",x,",",y,") is = ", math.atan2(x,y))

x = 0.2345
y = 1.234
print("atan2(",x,",",y,") is = ", math.atan2(x,y))

x = -5
y = 5
print("atan2(",x,",",y,") is = ", math.atan2(x,y))

x = 10
y = 20.23
print("atan2(",x,",",y,") is = ", math.atan2(x,y))
```

Output

```atan2( -1 , 1 ) is =  -0.7853981633974483
atan2( 0.2345 , 1.234 ) is =  0.18779323183177443
atan2( -5 , 5 ) is =  -0.7853981633974483
atan2( 10 , 20.23 ) is =  0.45908957477179374
```

TypeError example

```# python code to demonstrate example of
# math.atan2() method with an exception

# importing math module
import math

# numbers
x = "2"
y = "34"
print("atan2(",x,",",y,") is = ", math.atan2(x,y))
```

Output

```Traceback (most recent call last):
File "/home/main.py", line 10, in <module>
print("atan2(",x,",",y,") is = ", math.atan2(x,y))
TypeError: a float is required
```

Preparation