# Sum of cubes of first n natural numbers Calculator

## Calculating the Sum of Cubes of the First n Natural Numbers

The sum of the cubes of the first **n** natural numbers can be calculated using a specific formula. This formula provides a convenient method to determine the sum without manually calculating the cube of each number and adding them together.

The formula used is:

\(\text{Sum} = \left(\dfrac{ n(n+1)}{2}\right)^2\)

Where:

**n**represents the number of natural numbers.

This can be expressed as:

\( 1^3 + 2^3 + 3^3 + ... + n^3 \)

## Examples

Let’s explore some examples to understand how this formula is applied in practice.

### 1. Calculate the sum of cubes of the first 8 natural numbers.

#### Answer

To begin, we determine the value of **n**:

**Given:**

**n**= 8

Next, we apply the standard formula:

**Formula:**

\( \text{Sum} = \left(\dfrac{ n(n+1)}{2}\right)^2 \)

We substitute the value of **n** into the formula to calculate the sum:

**Substitution:**

\( \text{Sum} = \left(\dfrac{8(8+1)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{8(9)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{72}{2}\right)^2 \)

\( \text{Sum} = (36)^2 \)

\( \text{Sum} = 1296 \)

Finally, we conclude with the result:

**Result:**

∴ The sum of cubes of the first 8 natural numbers is 1296.

### 2. What is the sum of the cubes of the first 5 natural numbers?

#### Answer

We start by determining the value of **n**:

**Given:**

**n**= 5

Next, we use the established formula to find the sum:

**Formula:**

\( \text{Sum} = \left(\dfrac{ n(n+1)}{2}\right)^2 \)

We substitute **n** into the formula and simplify:

**Substitution:**

\( \text{Sum} = \left(\dfrac{5(5+1)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{5(6)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{30}{2}\right)^2 \)

\( \text{Sum} = (15)^2 \)

\( \text{Sum} = 225 \)

The result is:

**Result:**

∴ The sum of cubes of the first 5 natural numbers is 225.

### 3. Calculate the sum of the cubes of the first 10 natural numbers.

#### Answer

We first identify the value of **n**:

**Given:**

**n**= 10

Next, we apply the formula to calculate the sum:

**Formula:**

\( \text{Sum} = \left(\dfrac{ n(n+1)}{2}\right)^2 \)

We then substitute **n** into the formula and perform the calculation:

**Substitution:**

\( \text{Sum} = \left(\dfrac{10(10+1)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{10(11)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{110}{2}\right)^2 \)

\( \text{Sum} = (55)^2 \)

\( \text{Sum} = 3025 \)

The final result is:

**Result:**

∴ The sum of cubes of the first 10 natural numbers is 3025.

### 4. Find the sum of cubes of the first 12 natural numbers.

#### Answer

We begin by determining **n**:

**Given:**

**n**= 12

Next, we use the standard formula to perform the calculation:

**Formula:**

\( \text{Sum} = \left(\dfrac{ n(n+1)}{2}\right)^2 \)

We substitute the value of **n** into the formula and simplify:

**Substitution:**

\( \text{Sum} = \left(\dfrac{12(12+1)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{12(13)}{2}\right)^2 \)

\( \text{Sum} = \left(\dfrac{156}{2}\right)^2 \)

\( \text{Sum} = (78)^2 \)

\( \text{Sum} = 6084 \)

The final sum is:

**Result:**

∴ The sum of cubes of the first 12 natural numbers is 6084.

## Formula

To calculate the sum of cubes of first n natural numbers, you can use the following formula.

## Calculation

Once you enter the input values in the calculator, the output parameters are calculated.

## Frequently Asked Questions (FAQs)

### 1. What is the sum of cubes of the first n natural numbers?

The sum of cubes of the first n natural numbers is the total obtained by cubing each number from 1 to n and then adding them together. For example, if n is 3, the cubes are 1³, 2³, and 3³, which add up to 36.

### 2. How do you calculate the sum of cubes of the first n natural numbers?

To calculate the sum of cubes of the first n natural numbers, use the formula: \( \text{Sum} = \left( \frac{n(n+1)}{2} \right)^2 \). This formula finds the sum by squaring the sum of the first n natural numbers. For example, for n = 4, the sum is 100.

### 3. Why does the formula \( \left( \frac{n(n+1)}{2} \right)^2 \) work for the sum of cubes?

The formula \( \left( \frac{n(n+1)}{2} \right)^2 \) works because it is based on the pattern that the sum of cubes of the first n natural numbers is the square of the sum of the first n natural numbers. This relationship simplifies finding the total sum of cubes.

### 4. Can I use this formula for negative numbers?

No, the formula \( \left( \frac{n(n+1)}{2} \right)^2 \) is meant for natural numbers, which are positive integers starting from 1. It cannot be applied to negative numbers or zero because natural numbers do not include these values.

### 5. How does a calculator for the sum of cubes of first n natural numbers work?

The calculator applies the formula \( \left( \frac{n(n+1)}{2} \right)^2 \) to quickly compute the sum of cubes. You just need to input the value of n, and the calculator will automatically find the result without manual calculations, providing an accurate sum.

### 6. What is the sum of cubes for the first 5 natural numbers?

To find the sum of cubes for the first 5 natural numbers, use the formula \( \left( \frac{5(5+1)}{2} \right)^2 \). This gives \( \left( \frac{5*6}{2} \right)^2 = 225 \). Therefore, the sum of cubes from 1 to 5 is 225.

### 7. Is the sum of cubes of n natural numbers always a perfect square?

Yes, the sum of cubes of the first n natural numbers is always a perfect square because the formula \( \left( \frac{n(n+1)}{2} \right)^2 \) results in squaring a whole number. This ensures that the sum will always be a perfect square.

### 8. Why is finding the sum of cubes of the first n natural numbers useful?

The sum of cubes of the first n natural numbers is useful in various mathematical applications, such as algebra and calculus. It helps in solving problems related to sequences, series, and finding patterns in sums. It's also significant in some geometry and physics calculations.