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The square root of a number is a number that, when multiplied by itself, results in the original number. Hence, finding the square root is the converse of finding the square of a number. Here we will learn about the prime factorization method to find the square root of 12....Read MoreRead Less
The square root of number 12 is a number which when multiplied by itself results in 12. So, the square root of number 12 is a solution of the equation \(x^2\) = 12.
Finding the square and square root of a number are inverse operations. To find the square of a number you need to multiply the number by itself.
For example: To find the square of a number 4, we will multiply the number by itself, that is,
4 × 4 = 16
Whereas, to find the square root of 16, we will do the inverse operation.
A square root is represented by the radical symbol: ‘√’.
Since, \(4^2\) = 16
\(\Rightarrow \sqrt{16}=\sqrt{4^2}\) = 4
The number 12 is not a perfect square. Therefore, \(\sqrt{12}\) will result in an irrational number.
So, the value of \(\sqrt{12}\) can be approximated to the nearest integer or to the nearest tenth, hundredth and so on.
Let’s find the square root of 12 using the prime factorization method.
Step 1: Find the prime factors of 12
∴ 12 = 2 × 2 × 3
Step 2: Make pairs of identical numbers.
Since we do not have a pair of 3 we can write 3 as \(\sqrt{3}\) x \(\sqrt{3}\)
12 = \((2\times2)\times(\sqrt{3}\times\sqrt{3})\)
Step 3: Take a number from each pair and multiply them to get square root.
\(\sqrt{12}\) = 2 × \(\sqrt{3}\)
\(\Rightarrow \sqrt{12}\) = \(2\sqrt{3}\)
Since the value of \(\sqrt{3}\) = 1.732 (approx.)
\(\Rightarrow \sqrt{12}\) = 2 × 1.732 = 3.464 (approx.)
So, the square root of 12 is \(2\sqrt{3}\) or about 3.464
Each positive number has two square roots, one is positive and other is negative both having the same absolute value.
Let us understand this with example,
\(2\sqrt{3}\times2\sqrt{3}=12\)
\((-2\sqrt{3})\times(-2\sqrt{3})=12\)
[Since, multiplying two negatives results in a positive)]
From the above the square of \(-2\sqrt{3}\) is 12 and square of \(2\sqrt{3}\) is also 12, so we can say that square roots of 12 are \(2\sqrt{3}\) and \(-2\sqrt{3}\) both.
\(\sqrt{12}\) = ± \(2\sqrt{3}\)
In general,
Example 1: The area of a square crop field is 1200 \(m^2\). Find the side length and perimeter of the field.
Solution:
Let the side of the square crop field be ‘a’ m.
The area of the square field = \(a^2\) [Formula for area of a square]
\(\Rightarrow\) 1200 = \(a^2\) [Given area = 1200\(m^2\)]
\(\Rightarrow\sqrt{1200}\) = \(\sqrt{a^2}\) [Taking square root on both sides]
\(\Rightarrow\sqrt{12\times100}\) = \(\sqrt{a^2}\) [Rewrite 1200 as 12 x 100]
\(\Rightarrow\sqrt{12\times(2\times2)\times(5\times5)}\) = a [Prime factorize 100]
\(\Rightarrow\sqrt{12}\times\sqrt{(2\times2)\times(5\times5)}\) = a
\(\Rightarrow\sqrt{12}\times2\times5\) = a [Simplify]
\(\Rightarrow3.464\times10\) = a [Substitute 3.464 for \(\sqrt{12}\)]
∴ 34.64 = a [Simplify]
Hence, the side of the square crop field is about 34.64 m.
Now,
Perimeter of a square field = 4 × a [Formula for perimeter of a square]
= 4 × 34.64 [Substitute a = 34.64]
= 138.56 m
Therefore, the length of the side of the crop field is 34.64 m and its perimeter is about 138.56 m.
Example 2: Find the value of 5 multiplied by \(\sqrt{12}\).
Solution:
5 × \(\sqrt{12}\)
Substitute 3.464 for \(\sqrt{12}\)
5 × \(\sqrt{12}\) = 5 × 3.464
= 17.32 [Multiply]
Hence the value of 5 multiplied by \(\sqrt{12}\) is about 17.32.
Example 3: Find the value of \((3\sqrt{12}\times\sqrt{3})+(\sqrt{12}\times\sqrt{3})\) .
Solution:
Given expression: \((3\sqrt{12}\times\sqrt{3})+(\sqrt{12}\times\sqrt{3})\)
\((3\sqrt{12}\times\sqrt{3})+(\sqrt{12}\times\sqrt{3})\) = \((3\times2\sqrt{3}\times\sqrt{3})+(2\sqrt{3}\times\sqrt{3})\) [Substitute \(\sqrt{12}\) = \(2\sqrt{3}\)]
= (6 × 3) + (2 × 3) [Simplify]
= 18 + 6 [Multiply]
= 24 [Add]
Therefore, the value of the given expression is 24.
12 has two square roots just like any other number.
No, 12 is not a perfect square number.
The square root of 12 is = 3.464101615137………
So, the square root 12 is an irrational number because it is a non-terminating and non-repeating value.