Python Program to Find Cube of a Number

The Cube of a number is a simple mathematical operation where a number is multiplied by itself three times. In Python, there are multiple ways to find the cube of a number. In this article, we are going to discuss various approaches to calculating the cube of a number in Python.

How to find cube of a number?

The formula for finding the cube of a given number N is:

 Cube = N × N × N or N3

Example 1

• Input: 5
• Output: 125

Explanation:

The cube of 5 is: 5 × 5 × 5 = 125

Example 2

• Input: 3
• Output: 27

Explanation:

The cube of 5 is: 3 × 3 × 3 = 27

Different Approaches to Find the Cube of a Number

Using Direct Formula Approach

This is the simple and direct approach for finding the cube of a given number. In this approach, we use the direct method where we multiply the number by itself three times, which is represented by N3.

Steps for Implementation

• Take the input number.
• Calculate the cube using the formula: N × N × N.
• Output the result.

Implementation Code

# Define the number
n = 5

# Calculate the cube using the formula
cube = n * n * n

# Output the result
print(f"The cube of the number {n} is: {cube}")

Output:

The cube of the number 5 is: 125

Time Complexity: O(1)
Space Complexity: O(1)

Using the Exponentiation Operator

In this approach, we use the exponential operator (**) of Python to raise a number to a power. To find the cube of a number, we can raise the number to the power of 3 using the exponential operator.

Steps for Implementation

• Take the input number.
• Calculate the cube using the exponentiation operator N³.
• Output the result.

Implementation Code

# Define the number
n = 3

# Calculate the cube using exponentiation
cube = n ** 3

# Output the result
print(f"The cube of the number {n} is: {cube}")

Output:

The cube of the number 3 is: 27

Time Complexity: O(1)
Space Complexity: O(1)

Using the math.pow() Function

The math.pow() is an inbuilt function of Python's math module. This method can be used to calculate the power of numbers. To find the cube of a number, we use math.pow( n , 3).

Steps for Implementation

• First, import the math module.
• Now, use math.pow(n, 3) to calculate the cube.
• Output the result.
  

Implementation Code

import math

# Define the number
n = 3

# Calculate the cube using math.pow()
cube = math.pow(n, 3)

# Output the result
print(f"The cube of the number {n} is: {cube}")

Output

The cube of the number 3 is: 27.0

Time Complexity: O(1)
Space Complexity: O(1)

Using a Function

In this approach, we define a function that accepts a number as an argument and returns the cube of the number. This approach is reusable and allows us to calculate the cube of any number by calling the function multiple times.

Steps for Implementation

• Define a function that accepts a number and calculates its cube.
• Call the function with the required input.
• Output the result.
  

Implementation Code

# Function to calculate the cube
def calculate_cube(n):
 return n ** 3 # Using the exponentiation operator inside the function

# Call the function
n = 3
cube = calculate_cube(n)

# Output the result
print(f"The cube of the number {n} is: {cube}")

Output

The cube of the number 3 is: 27

Time Complexity: O(1)
Space Complexity: O(1)

Using a Loop (Multiplication)

This is a simple and iterative approach. In this approach, we use a loop to multiply the number by itself three times. This is not the most efficient method, but it is used to understand the iterative process.

Steps for Implementation

• Initialize a variable to hold the result.
• Multiply the number by itself three times inside a loop.
• Output the result

Implementation Code

# Define the number
n = 3

# Initialize result variable
result = 1

# Loop to multiply the number by itself 3 times
for _ in range(3):
    result *= n

# Output the result
print(f"The cube of the number {n} is: {result}")

Output:

The cube of the number 3 is: 27

Time Complexity: O(1)
Space Complexity: O(1)