# Python math.exp() Method

The Python math.exp() method is used to compute the Euler's number 'e' raised to the power of a numeric value.

The Euler’s number is simply defined as a mathematical expression that is usually used as the base of natural logarithms. It is a non-terminating and a non-recurring decimal number that holds the value of 2.718281828459045… However, the number is constricted to only two decimals in most problems to be solved, i.e., 2.71.

This Euler’s number is mostly used in problems that deal with exponential functions (either increasing or decreasing). The number is denoted by a letter e.

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.exp() method −

math.exp( x )


## Parameters

• x − This is the exponent value.

## Return Value

This method returns exponential of x: ex.

## Example

The following example shows the usage of the Python math.exp() method. In here, we are trying to find the exponential values of the Euler's number when it is raised to positive values.

import math

# Create two number objects with one integer and one float
x = 3
y = 5.6

# Calculate the exponent for both numbers
exp1 = math.exp(x)
exp2 = math.exp(y)

# Display the return values
print("The exponent of x is", exp1)
print("The exponent of y is", exp2)


When we run above program, it produces following result −

The exponent of x is 20.085536923187668
The exponent of y is 270.42640742615254


## Example

The result of the Euler's number raised to a number is always positive, even if the number is negative.

In the following example, we are creating two number objects with negative values and passing them as arguments to this method. The method then calculates the exponential value with these objects and returns them.

import math

# Create two number objects with one integer and one float
x = -5
y = -0.6

# Calculate the exponent for both numbers
exp1 = math.exp(x)
exp2 = math.exp(y)

# Display the return values
print("The exponent of x is", exp1)
print("The exponent of y is", exp2)


Once we compile and run the given program, the output is displayed as follows:

The exponent of x is 0.006737946999085467
The exponent of y is 0.5488116360940265


## Example

If the Euler's number is raised to an invalid number, the result will also be an invalid number.

Here, we are creating an object containing a NaN value in it. In Python, we usually create a NaN value object using float(). This object is then passed as an argument to the exp() method which calculates the exponential value of it.

import math

# Create a number objects with a float NaN value
x = float("nan")

# Calculate the exponent for NaN
exp = math.exp(x)

# Display the return values
print("The exponent of x is", exp)


Let us compile and run the program above, to produce the output as follows −

The exponent of x is nan


## Example

If the Euler's number is raised to either positive infinity or negative infinity, the return value will be positive infinity and 0 respectively.

In this example, we are creating an object containing a infinity values in it. In Python, we usually create a infinity value objects using float(). This object is then passed as an argument to the exp() number which calculates the exponential value of it.

import math

# Create two number objects with float infinity values
x = float("INF")
y = float("-INF")

# Calculate the exponent for NaN
exp1 = math.exp(x)
exp2 = math.exp(y)

# Display the return values
print("The exponent of x is", exp1)
print("The exponent of y is", exp2)


The exponent of x is inf
The exponent of y is 0.0


## Example

If we pass a non-numeric value as an argument to this method, a TypeError is raised.

import math

# Create a string object
x = 'a'

# Calculate the exponent for x
exp = math.exp(x)

# Display the return values
print("The exponent of x is", exp)


The output for the program above is displayed as follows −

Traceback (most recent call last):
File "main.py", line 7, in
exp = math.exp(x)
TypeError: must be real number, not str

python_maths.htm