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Last updated on December 2nd, 2024

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Square Root of 121

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Foundation
Intermediate
Advance Topics

The square root of 121 is a value “y” such that when “y” is multiplied by itself → y ⤫ y, the result is 121. The number 121 has a unique non-negative square root, called the principal square root.

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What Is the Square Root of 121?

The square root of 121 is ±11, where 11 is the positive solution of the equation x2 = 121. Finding the square root is just the inverse of squaring a number and hence, squaring 11 will result in 121. 
The square root of 121 is written as √121 in radical form, where the ‘√’  sign is called  the “radical” sign. In exponential form, it is written as (121)1/2 
 

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Finding the Square Root of 121

We can find the square root of 121 through various methods. They are:

 

  • Prime factorization method

 

  • Long division method

 

  • Approximation/Estimation method
     
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Square Root of 121 By Prime Factorization Method

The prime factorization of 121 can be found by dividing the number by prime numbers and continuing to divide the quotients until they can’t be separated anymore, i.e., we first prime factorize 121 and then make pairs of two to get the square root.

 

So, Prime factorization of 121 = 11 × 11


Square root of 121= √[11 × 11] = 11

 

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Square Root of 121 By Long Division Method

This method is used for obtaining the square root for non-perfect squares, mainly. It usually involves the division of the dividend by the divisor, getting a quotient and a remainder too sometimes.


Follow the steps to calculate the square root of 121:


 Step 1: Write the number 121 and draw a bar above the pair of digits from right to left.


 Step 2: Now, find the greatest number whose square is less than or equal to 1. Here, it is
              1 because 12=1 < =1


Step 3: now divide 121 by 1 (the number we got from Step 2) such that we get 1 as a quotient, and we get a remainder.  Double the divisor 1, we get 2, and then the largest possible number A1=1 is chosen such that when 1 is written beside the new divisor 2, a 2-digit number is formed →21, and multiplying 1 with 21 gives 21, which
 when subtracted from 21, gives 0


Repeat this process until you reach the remainder of 0. 
 
Step 4: The quotient obtained is the square root of 121. In this case, it is 11.

 

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Square Root of 121 By Subtraction Method

We know that the sum of the first n odd numbers is n2. We will use this fact to find square roots through the repeated subtraction method. Furthermore, we just have to subtract consecutive odd numbers from the given number, starting from 1. The square root of the given number will be the count of the number of steps required to obtain 0. Here are the steps:


Step 1: take the number 121 and then subtract the first odd number from it. Here, in this case, it is 121-1=120


Step 2: we have to subtract the next odd number from the obtained number until it comes zero as a result. Now take the obtained number (from Step 1), i.e., 120, and again subtract the next odd number after 1, which is 3, → 120-3=117. Like this, we have to proceed further.


Step 3: now we have to count the number of subtraction steps it takes to yield 0 finally. Here, in this case, it takes 11 steps 

 


So, the square root is equal to the count, i.e., the square root of 121 is ±11.

 


 

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Common Mistakes and How to Avoid Them in the Square Root of 121

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Square Root of 121 Examples

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Problem 1

Find √(121⤬36) ?

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Explanation

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Problem 2

What is √121 multiplied by 4 ?

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Explanation

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Problem 3

Find the radius of a circle whose area is 121π cm^2.

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Explanation

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Problem 4

Find the length of a side of a square whose area is 121 cm^2

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Explanation

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Problem 5

Find √121 / √100

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Explanation

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FAQs on 121 Square Root

1.What is the cube root of 121?

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2.What type of number is 121?

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3.Is 121 a perfect square or non-perfect square?

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4.Is the square root of 121 a rational or irrational number?

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5.What are the two square roots of 121?

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Important Glossaries for Square Root of 121

  • Exponential form:  An algebraic expression that includes an exponent. It is a way of expressing the numbers raised to some power of their factors. It includes continuous multiplication involving base and exponent. Ex: 2 × 2 × 2 × 2 = 16 Or, 2 4 = 16, where 2 is the base, 4 is the exponent 

 

  • Prime Factorization:  Expressing the given expression as a product of its factors. Ex: 48=2 × 2 × 2 × 2 × 3

 

  • Prime Numbers: Numbers which are greater than 1, having only 2 factors as →1 and Itself. Ex: 1,3,5,7,....

 

  • Rational numbers and Irrational numbers: The Number which can be expressed as p/q, where p and q are integers and q not equal to 0 are called Rational numbers. Numbers which cannot be expressed as p/q, where p and q are integers and q not equal to 0 are called Irrational numbers. 

 

  • Perfect and non-perfect square numbers: Perfect square numbers are those numbers whose square roots do not include decimal places. Ex: 4,9,25 Non-perfect square numbers are those numbers whose square roots comprise decimal places. Ex :3, 8, 24
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Jaskaran Singh Saluja

About the Author

Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.

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Fun Fact

: He loves to play the quiz with kids through algebra to make kids love it.

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