Python math.atan() Method

The Python math.atan() method returns the arc tangent of a number in radians.

The arc tangent of an angle is defined as the inverse of a tangent function. Therefore, the domain of the arc tangent function is the range of the tangent function, i.e., [-infinity, infinity]; and its range is obtained in the form of radians. They can be converted into degrees using the degrees() method, if required.

Note − This function is not accessible directly, so we need to import math module and then we need to call this function using math static object.

Syntax

Following is the syntax for the Python math.atan() method −

math.atan(x)

Parameters

• x − This must be a numeric value.

Return Value

This method returns arc tangent of x in radians.

Example

The following example shows the usage of the Python math.atan() method. In here, we are trying to find the arc tangent values of 0, -1 and 1.

import math

zero = math.atan(0)
neg_one = math.atan(-1)
pos_one = math.atan(1)

print("Arc Tangent value of 0:", zero)
print("Arc Tangent value of -1:", neg_one)
print("Arc Tangent value of 1:", pos_one)

When we run above program, it produces following result −

Arc Tangent value of 0: 0.0
Arc Tangent value of -1: -0.7853981633974483
Arc Tangent value of 1: 0.7853981633974483

Example

Now let us try to convert the return values obtained from the method in the previous example into degrees using the degrees() method.

In this example, three objects containing the values 0, -1 and 1 are created. Using the atan() method, the arc tangent values of these objects are calculated in radians; which are later converted into degrees using the degrees() method.

import math

zero = math.atan(0)
neg_one = math.atan(-1)
pos_one = math.atan(1)

print("Arc Tangent value of 0:", math.degrees(zero))
print("Arc Tangent value of -1:", math.degrees(neg_one))
print("Arc Tangent value of 1:", math.degrees(pos_one))

On executing the program above, the result is produced as follows −

Arc Tangent value of 0: 0.0
Arc Tangent value of -1: -45.0
Arc Tangent value of 1: 45.0

Example

Let us also try to pass non-standard tangent ratios as arguments to this method, to calculate the arc tangent values of them.

import math

atan1 = math.atan(3.4)
atan2 = math.atan(-8.7)

print("Arc Tangent value of 3.4:", atan1)
print("Arc Tangent value of -8.7:", atan2)

Now, if we compile and run the program above, the output is displayed as follows −

Arc Tangent value of 3.4: 1.2847448850775784
Arc Tangent value of -8.7: -1.4563560215248332