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Understanding Square Root and Cube Root in Mathematics

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Square Root and Cube Root Formula Properties and Solved Examples

Square Root and Cube Root are the important concepts used in Mathematics. As we have seen square numbers can be represented by a two-dimensional square, a cube number can be represented by a three-dimensional cube.


We calculate the area of a square as side x side i.e side2, but if we have to calculate the side of a square we need to take the square root of the area. Thus we can say that the square root is the inverse operation of squaring a number.


Similarly, when we find the volume of the cube, we have volume = side3, but if we want to find the side of a cube we have to take the cube root of the volume. Thus, we can say that the cube root is the inverse operation of cubing a number.the square root and cube root symbols are \[\sqrt{}\]and ∛ respectively.


On this page, we will be learning square roots and cube roots definition, square root, and cube root symbol and square root and cube root example.


Square Roots and Cube Roots Symbol

Square Root

The square root of a number x is that number which when multiplied by itself gives the number x itself. The number x is a perfect square.


For Example, 22 =4, or the square root of 4 is 2

32 =9, or the square root of 9 is 3

42 = 16, or the square root of 16 is 4

The symbol of the square root is \[\sqrt{}\]

Therefore, the square root of 4 is represented as \[\sqrt{4}\] = 2.

And the square root of 9 is represented as \[\sqrt{9}\] = 3 and so on.


Cube Root

The cube root of a number a is that number which when multiplied by itself three times gives the number ‘a’ itself. 

For Example, 23 =8, or the cube root of 8 is 2

33 = 27, or the cube root of 27 is 3

43 = 64, or the cube root of 64 is 4

The symbol of the cube root is a 1/3  or  ∛

Thus, the cube root of 8 is represented as \[\sqrt[3]{8}\] = 2 and that of 27 is represented as \[\sqrt[3]{27}\]= 3

and so on.


Properties of Square Root:

  • If the unit digit of a number is 2, 3, 7, and 8 then its square root is not a natural number.

  • If a number ends in an odd number of zeros, then its square root is not a natural number.

  • The square root of an even number is even and that of an odd number is odd.

  • Negative numbers have no squares root in a set of real numbers.


Properties of Cube Root

  • Cube root of all the odd numbers is an odd number. For example: \[\sqrt[3]{27}\]= 3, \[\sqrt[3]{125}\] = 5.

  • Cube root of all the even natural numbers is even. For example: \[\sqrt[3]{8}\] = 2,\[\sqrt[3]{64}\] = 4.

  • The cube root of a negative integer always results in negative.


Methods of Finding the Squares Roots and Cube Roots:

First, five number’s square root and cube root are easy to remember. But when we have to find square root and cube root of large numbers we can use the following methods to find it. They are

  1. Prime Factorisation Method

  2. Long Division method


This method will help you to find the square roots and cube root of a given number but if the square root and cube root of the first 10 numbers are memorized it will help you solve your problems more quickly. Here is the  square root and cube root table format, which will help you to memorize these square roots and cube roots.


Square Root and Cube Root of 1 to 15

Square root list and cube root list of 1 to 15 will help you to solve the most time consuming long equations within no time. This square root and cube root table will be beneficial to you at every step.


Square Root and Cube Root Table

Square Root of a Number

Number

Cube Root of a Number

Number

\[\sqrt{4}\]

2

\[\sqrt[3]{8}\]

2

\[\sqrt{9}\]

3

\[\sqrt[3]{27}\]

3

\[\sqrt{16}\]

4

\[\sqrt[3]{64}\]

4

\[\sqrt{25}\]

5

\[\sqrt[3]{135}\]

5

\[\sqrt{36}\]

6

\[\sqrt[3]{216}\]

6

\[\sqrt{49}\]

7

\[\sqrt[3]{343}\]

7

\[\sqrt{64}\]

8

\[\sqrt[3]{512}\]

8

\[\sqrt{81}\]

9

\[\sqrt[3]{729}\]

9

\[\sqrt{100}\]

10

\[\sqrt[3]{1000}\]

10

\[\sqrt{121}\]

11

\[\sqrt[3]{1331}\]

11

\[\sqrt{144}\]

12

\[\sqrt[3]{1728}\]

12

\[\sqrt{169}\]

13

\[\sqrt[3]{2197}\]

13

\[\sqrt{196}\]

14

\[\sqrt[3]{2744}\]

14

\[\sqrt{225}\]

15

\[\sqrt[3]{3375}\]

15

Make use of this square root list and cube root list and solve the below square root and cube root example.


Solved Examples

Square root and Cube root example

Example 1: Find the cube root of 2744

Solution :

By Prime Factorisation method

Step 1: First we take the prime factors of a given number

2744 = 2 x 7 x 2 x 2 x 7 x 7

Step 2: Form groups of three similar factors

= 2 x 2 x 2 x 7 x 7 x 7

          Step 3: Take out one factor from each group and multiply.

= 23 x 73

= 143

Therefore, \[\sqrt[3]{2744}\]= 14

Example 2: Find the cube root of 1728 by long division method

Solution:

2

1728

2

864

2

432

2

216

2

108

2

54

3

27

3

9

3

3


1

Now,

\[\sqrt[3]{1728}\]= \[\sqrt[3]{2X2X2X2X2X2X3X3}\]

= 2 x 2 x 3

= 12


Quiz

Some more square root and cube root examples to solve.

  1. Estimate the square root of 666

  2. Find the value of \[\sqrt{256}\]

  3. Using prime factorization, find the value of \[\sqrt[3]{1331}\]

  4. Using long division method, find the value of \[\sqrt[3]{729}\]

FAQs on Understanding Square Root and Cube Root in Mathematics

1. What is a square root in Maths?

A square root of a number is a value that, when multiplied by itself, gives the original number. In other words, if x² = n, then x is the square root of n.

For example:

  • The square root of 25 is 5 because 5 × 5 = 25.
  • The square root of 16 is 4.
The symbol used for square root is , such as √25 = 5.

2. What is a cube root in Maths?

A cube root of a number is a value that, when multiplied by itself three times, gives the original number. In other words, if x³ = n, then x is the cube root of n.

For example:

  • The cube root of 27 is 3 because 3 × 3 × 3 = 27.
  • The cube root of 8 is 2.
The symbol used for cube root is , such as ∛27 = 3.

3. How do you find the square root of a number?

You can find the square root of a number using prime factorization, long division method, or a calculator. For perfect squares, follow these steps:

  • Step 1: Write the number as a product of prime factors.
  • Step 2: Pair identical factors.
  • Step 3: Take one factor from each pair.
Example: Find √36
  • 36 = 2 × 2 × 3 × 3
  • Pairs: (2 × 2), (3 × 3)
  • √36 = 6

4. How do you find the cube root of a number?

You can find the cube root of a number using prime factorization by grouping factors in triples. For perfect cubes, follow these steps:

  • Step 1: Write the number as a product of prime factors.
  • Step 2: Group identical factors in sets of three.
  • Step 3: Take one factor from each group.
Example: Find ∛64
  • 64 = 2 × 2 × 2 × 2 × 2 × 2
  • Groups: (2 × 2 × 2), (2 × 2 × 2)
  • ∛64 = 4

5. What is the difference between square root and cube root?

The main difference is that a square root involves a power of 2, while a cube root involves a power of 3.

  • Square root: If x² = n, then x = √n.
  • Cube root: If x³ = n, then x = ∛n.
  • Example: √16 = 4, but ∛16 is not a whole number.
  • Negative numbers: Square roots of negative numbers are not real, but cube roots can be negative (∛−8 = −2).

6. What is the formula for square root and cube root?

The formula for square root is √n = n1/2 and for cube root is ∛n = n1/3. These are fractional exponent forms.

  • Square root form: n1/2
  • Cube root form: n1/3
  • Example: 251/2 = 5 and 271/3 = 3
This form is useful in algebra and exponent rules.

7. Can a negative number have a square root or cube root?

A negative number does not have a real square root, but it does have a real cube root. This is because squaring a number always gives a non-negative result, while cubing can give a negative result.

  • √(−9) is not a real number.
  • ∛(−8) = −2 because (−2)³ = −8.
This is an important difference between square roots and cube roots in real numbers.

8. What are perfect squares and perfect cubes?

A perfect square is a number that is the square of an integer, and a perfect cube is a number that is the cube of an integer.

  • Perfect squares: 1, 4, 9, 16, 25 (e.g., 5² = 25)
  • Perfect cubes: 1, 8, 27, 64 (e.g., 4³ = 64)
These numbers have whole number square roots or cube roots.

9. How do you simplify square roots and cube roots?

To simplify square roots or cube roots, factor the number and take out perfect squares or perfect cubes from under the radical.

Example (Square root):

  • √18 = √(9 × 2)
  • = 3√2
Example (Cube root):
  • ∛54 = ∛(27 × 2)
  • = 3∛2
This method helps simplify radicals into simplest form.

10. Where are square roots and cube roots used in real life?

Square roots and cube roots are used in geometry, physics, engineering, and real-life measurements involving area and volume.

  • Square roots are used to find the side of a square from its area.
  • Cube roots are used to find the side of a cube from its volume.
  • In physics, square roots appear in speed and distance formulas.
For example, if the area of a square is 49 cm², the side length is √49 = 7 cm.