What are those mysterious square roots that often confuse students and complicate their lives? The truth is that to understand them, we need to grasp the concept of the inverse operation.

What is a square root?

When we solve an exercise like 5=252 5=25^2 , it's clear that 5 5 times 5 5 (that is, multiplying the number by itself) results in 25 25 . This is the concept of a power, or to be more precise, a square power, which to apply, we must multiply the figure or the number by itself.

The concept of "square root" refers to the inverse operation of squaring numbers.

That is, if we have X2=25X^2=25 and we want to find the value of XX, what we need to do is perform an identical operation on both sides of the equation.

A - The concept of square root refers to the inverse operation of squaring numbers

This operation is the square root.

So, we have: X2=25\sqrt{X^2} = \sqrt{25} and the result is X=5 X=5 .

Suggested Topics to Practice in Advance

  1. Exponents and Roots - Basic
  2. Exponents and Exponent rules
  3. Basis of a power
  4. The exponent of a power
  5. Powers

Practice Square Roots

Examples with solutions for Square Roots

Exercise #1

Choose the largest value

Video Solution

Step-by-Step Solution

Let's begin by calculating the numerical value of each of the roots in the given options:

25=516=49=3 \sqrt{25}=5\\ \sqrt{16}=4\\ \sqrt{9}=3\\ We can determine that:

5>4>3>1 Therefore, the correct answer is option A

Answer

25 \sqrt{25}

Exercise #2

49= \sqrt{49}=

Video Solution

Step-by-Step Solution

To solve this problem, we follow these steps:

  • Step 1: Understand that finding the square root of a number means determining what number, when multiplied by itself, equals the original number.
  • Step 2: Identify the numbers that could potentially be the square root of 4949. These are ±7 \pm7, but by convention, the square root function typically refers to the non-negative root.
  • Step 3: Calculate 7×7=497 \times 7 = 49. This confirms that 49=7 \sqrt{49} = 7.
  • Step 4: Verify using the problem's multiple-choice answers to ensure 77 is among them, confirming choice number .

Therefore, the solution to the problem 49 \sqrt{49} is 7 7 .

Answer

7

Exercise #3

36= \sqrt{36}=

Video Solution

Step-by-Step Solution

Let's solve the problem step by step:

  • Step 1: Understand what the square root means.
  • The square root of a number nn is a value that, when multiplied by itself, equals nn. This is written as x=nx = \sqrt{n}.

  • Step 2: Apply this definition to the number 3636.
  • We are looking for a number xx such that x2=36x^2 = 36. This translates to finding x=36x = \sqrt{36}.

  • Step 3: Determine the correct number.
  • We know that 6×6=366 \times 6 = 36. Therefore, the principal square root of 3636 is 66.

Thus, the solution to the problem is 36=6 \sqrt{36} = 6 .

Among the given choices, the correct one is: Choice 1: 66.

Answer

6

Exercise #4

64= \sqrt{64}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Recognize what finding a square root means
  • Step 2: List known perfect squares to identify which one results in 64
  • Step 3: Verify the square root by calculation

Now, let's work through each step:
Step 1: To find the square root of 64, we seek a number that, when multiplied by itself, equals 64.
Step 2: Consider the sequence of perfect squares: 12=1 1^2 = 1 , 22=4 2^2 = 4 , 32=9 3^2 = 9 , 42=16 4^2 = 16 , 52=25 5^2 = 25 , 62=36 6^2 = 36 , 72=49 7^2 = 49 , 82=64 8^2 = 64 .
Step 3: We see that 82=64 8^2 = 64 . Therefore, the square root of 64 is 8.

Therefore, the solution to this problem is 8 8 .

Answer

8

Exercise #5

Solve the following exercise:

x2= \sqrt{x^2}=

Video Solution

Step-by-Step Solution

In order to simplify the given expression, we will use two laws of exponents:

a. The definition of root as an exponent:

an=a1n \sqrt[n]{a}=a^{\frac{1}{n}} b. The law of exponents for power of a power:

(am)n=amn (a^m)^n=a^{m\cdot n}

Let's start with converting the square root to an exponent using the law mentioned in a':

x2=(x2)12= \sqrt{x^2}= \\ \downarrow\\ (x^2)^{\frac{1}{2}}= We'll continue using the law of exponents mentioned in b' and perform the exponent operation on the term in parentheses:

(x2)12=x212x1=x (x^2)^{\frac{1}{2}}= \\ x^{2\cdot\frac{1}{2}}\\ x^1=\\ \boxed{x} Therefore, the correct answer is answer a'.

Answer

x x

Exercise #6

441= \sqrt{441}=

Video Solution

Step-by-Step Solution

The root of 441 is 21.

21×21= 21\times21=

21×20+21= 21\times20+21=

420+21=441 420+21=441

Answer

21 21

Exercise #7

x=1 \sqrt{x}=1

X=? X=?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Square both sides of the equation.
  • Step 2: Simplify the resulting expression.

Now, let's work through each step:

Step 1: We have the equation x=1 \sqrt{x} = 1 .
Square both sides:

(x)2=12 (\sqrt{x})^2 = 1^2

Step 2: Simplify both sides of the equation.

The left side simplifies to x x , since the square and the square root cancel each other out:

x=1 x = 1

The right side simplifies to 1, so we have:

x=1 x = 1

Therefore, the solution to the problem is x=1 x = 1 .

Answer

1

Exercise #8

x=2 \sqrt{x}=2

Video Solution

Step-by-Step Solution

To solve the problem, follow these steps:

  • Step 1: Begin with the equation x=2\sqrt{x} = 2.
  • Step 2: Square both sides of the equation to eliminate the square root.
  • Step 3: Simplify the resulting equation to find xx.

Now, let's proceed through each step:
Step 1: The given equation is x=2\sqrt{x} = 2.
Step 2: Square both sides: (x)2=22(\sqrt{x})^2 = 2^2.
Step 3: This simplifies to x=4x = 4.

Therefore, the value of xx that satisfies x=2\sqrt{x} = 2 is x=4 x = 4 .

Matching this solution with the provided choices, the correct answer is choice 3, which is 4.

Answer

4

Exercise #9

x=6 \sqrt{x}=6

Video Solution

Step-by-Step Solution

To solve this problem, we will perform the following steps:

  • Step 1: Square both sides of the equation x=6 \sqrt{x} = 6 .
  • Step 2: Simplify the equation to find x x .

Let's carry out each step in detail:

Step 1: Square both sides of the equation:
 (x)2=62\ (\sqrt{x})^2 = 6^2

Step 2: Simplify the equation:
Since (x)2=x(\sqrt{x})^2 = x, we have x=36 x = 36 .

Therefore, the value of x x is 36.

Answer

36

Exercise #10

4= \sqrt{4}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll determine the square root of the number 4.

  • Step 1: Recognize that the square root of a number is asking for a value that, when multiplied by itself, yields the original number. Here, we seek a number yy such that y2=4y^2 = 4.
  • Step 2: Identify that 44 is a perfect square. The numbers 22 and 2-2 both satisfy the equation 22=42^2 = 4 and (2)2=4(-2)^2 = 4.
  • Step 3: We usually consider the principal square root, which is the non-negative version. Thus, 4=2\sqrt{4} = 2.

Therefore, the solution to the problem is 2, which corresponds to the correct choice from the given options.

Answer

2

Exercise #11

9= \sqrt{9}=

Video Solution

Step-by-Step Solution

To solve this problem, we want to find the square root of 9.

Step 1: Recognize that a square root is a number which, when multiplied by itself, equals the original number. Thus, we are seeking a number x x such that x2=9 x^2 = 9 .

Step 2: Note that 9 is a common perfect square: 9=3×3 9 = 3 \times 3 . Therefore, the square root of 9 is the number that, when multiplied by itself, gives 9. This number is 3.

Step 3: Since we are interested in the principal square root, we consider only the non-negative value. Hence, the principal square root of 9 is 3.

Therefore, the solution to the problem is 3 3 .

Answer

3

Exercise #12

16= \sqrt{16}=

Video Solution

Step-by-Step Solution

To determine the square root of 16, follow these steps:

  • Identify that we are looking for the square root of 16, which is a number that, when multiplied by itself, equals 16.
  • Recall the basic property of perfect squares: 4×4=16 4 \times 4 = 16 .
  • Thus, the square root of 16 is 4.

Hence, the solution to the problem is the principal square root, which is 4 4 .

Answer

4

Exercise #13

36= \sqrt{36}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Understand the definition of a square root.
  • Step 2: Identify which integer, when squared, gives 36.
  • Step 3: Verify this integer meets the required condition.
  • Step 4: Choose the correct answer from the given choices.

Now, let's work through each step:
Step 1: A square root of a number is a value that, when multiplied by itself, gives the original number. Here, we want y y such that y2=36 y^2 = 36 .
Step 2: We test integer values to find which one squared equals 36. Testing y=1,2,3,4,5, y = 1, 2, 3, 4, 5, and 6 6 gives:
- 12=1 1^2 = 1
- 22=4 2^2 = 4
- 32=9 3^2 = 9
- 42=16 4^2 = 16
- 52=25 5^2 = 25
- 62=36 6^2 = 36

Step 3: The integer 6 6 satisfies 62=36 6^2 = 36 . Therefore, 36=6 \sqrt{36} = 6 .

Step 4: The correct choice from the given answer choices is 6 (Choice 4).

Hence, the square root of 36 is 6 \mathbf{6} .

Answer

6

Exercise #14

64= \sqrt{64}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll determine the square root of 64, following these steps:

  • Step 1: Identify the number whose square root we need to find. The number given is 64.
  • Step 2: Determine which number, when multiplied by itself, equals 64.
  • Step 3: Recall that 8×8=64 8 \times 8 = 64 .

Now, let's work through each step:

Step 1: We are tasked with finding 64 \sqrt{64} . The problem involves identifying the number which, when squared, results in 64.
Step 2: To find this number, we'll check our knowledge of squares. We know that 8 is a significant integer whose square results in 64.
Step 3: Compute: 8×8=64 8 \times 8 = 64 . Hence, 8 8 meets the requirement.

We find that the solution to the problem is 64=8 \sqrt{64} = 8 .

Answer

8

Exercise #15

100= \sqrt{100}=

Video Solution

Step-by-Step Solution

The task is to find the square root of the number 100. The square root operation seeks a number which, when squared, equals the original number. For any positive integer, if x2=100 x^2 = 100 , then x x should be our answer.

Step 1: Recognize that 100 is a perfect square. This means there exists an integer x x such that x×x=100 x \times x = 100 . Generally, we recall basic squares such as:

  • 12=1 1^2 = 1
  • 22=4 2^2 = 4
  • 32=9 3^2 = 9
  • and so forth, up to 102 10^2

Step 2: Checking integers, we find that:

102=10×10=100 10^2 = 10 \times 10 = 100

Step 3: Confirm the result: Since 10×10=100 10 \times 10 = 100 , then 100=10 \sqrt{100} = 10 .

Step 4: Compare with answer choices. Given that one of the choices is 10, and 100=10 \sqrt{100} = 10 , choice 1 is correct.

Therefore, the square root of 100 is 10.

Answer

10

Topics learned in later sections

  1. Square Root of a Negative Number