Square root of a product

๐Ÿ†Practice product property of square roots

The square root of a product

When we encounter a root that encompasses the entirety of the product, we can decompose the factors of the products and leave a separate root for each of them. Let's not forget to leave the multiplication sign between the factors we have extracted.

Let's put it this way:
(aโ‹…b)=aโ‹…b\sqrt{(a\cdot b)}=\sqrt{a}\cdot\sqrt{b}

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Test yourself on product property of square roots!

einstein

Choose the expression that is equal to the following:

\( \sqrt{a}\cdot\sqrt{b} \)

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Let's look at this in the example

4โ‹…400\sqrt{4\cdot400}
According to the rule of the root of a product, we can break down the factors and leave the root of each factor separately while maintaining the multiplication operation between them:
We will break it down and obtain:
4โ‹…400\sqrt{4}\cdot\sqrt{400}
2โˆ—20=402*20=40

If you are interested in this article, you might also be interested in the following articles:

Laws of Radicals

Root of the Quotient

Radication

Combining Powers and Roots

In the blog of Tutorela you will find a variety of articles about mathematics.


Examples and exercises with solutions of the root of a product

Exercise #1

Choose the expression that is equal to the following:

aโ‹…b \sqrt{a}\cdot\sqrt{b}

Video Solution

Step-by-Step Solution

To solve this problem, we can use the product property of square roots.

  • Step 1: Recognize the expression aโ‹…b \sqrt{a} \cdot \sqrt{b} .
  • Step 2: Apply the product property: aโ‹…b=aโ‹…b \sqrt{a} \cdot \sqrt{b} = \sqrt{a \cdot b} .

This tells us that the original expression, aโ‹…b \sqrt{a} \cdot \sqrt{b} , simplifies to aโ‹…b \sqrt{a \cdot b} .

Thus, the equivalent expression is aโ‹…b \sqrt{a \cdot b} .

Among the given choices, choice 2 aโ‹…b \sqrt{a\cdot b} is the correct one.

Answer

aโ‹…b \sqrt{a\cdot b}

Exercise #2

Solve the following exercise:

30โ‹…1= \sqrt{30}\cdot\sqrt{1}=

Video Solution

Step-by-Step Solution

Let's start with a reminder of the definition of a root as a power:

an=a1n \sqrt[n]{a}=a^{\frac{1}{n}}

We will then use the fact that raising the number 1 to any power always yields the result 1, particularly raising it to the power of half of the square root (which we obtain by using the definition of a root as a power mentioned earlier).

In other words:

30โ‹…1=โ†“30โ‹…12=30โ‹…112=30โ‹…1=30 \sqrt{30}\cdot\sqrt{1}= \\ \downarrow\\ \sqrt{30}\cdot\sqrt[2]{1}=\\ \sqrt{30}\cdot 1^{\frac{1}{2}}=\\ \sqrt{30} \cdot1=\\ \boxed{\sqrt{30}}

Therefore, the correct answer is answer C.

Answer

30 \sqrt{30}

Exercise #3

Solve the following exercise:

1โ‹…25= \sqrt{1}\cdot\sqrt{25}=

Video Solution

Step-by-Step Solution

To solve the expression 1โ‹…25 \sqrt{1} \cdot \sqrt{25} , we will use the Product Property of Square Roots.

According to the property, we have:

1โ‹…25=1โ‹…25\sqrt{1} \cdot \sqrt{25} = \sqrt{1 \cdot 25}

First, calculate the product inside the square root:

1โ‹…25=251 \cdot 25 = 25

Now the expression simplifies to:

25\sqrt{25}

Finding the square root of 25 gives us:

55

Thus, the value of 1โ‹…25 \sqrt{1} \cdot \sqrt{25} is 5\boxed{5}.

After comparing this solution with the provided choices, we see that the correct answer is choice 3.

Answer

5 5

Exercise #4

Solve the following exercise:

16โ‹…1= \sqrt{16}\cdot\sqrt{1}=

Video Solution

Step-by-Step Solution

Let's start by recalling how to define a root as a power:

an=a1n \sqrt[n]{a}=a^{\frac{1}{n}}

Next, we will remember that raising 1 to any power will always yield the result 1, even the half power of the square root.

In other words:

16โ‹…1=โ†“16โ‹…12=16โ‹…112=16โ‹…1=16=4 \sqrt{16}\cdot\sqrt{1}= \\ \downarrow\\ \sqrt{16}\cdot\sqrt[2]{1}=\\ \sqrt{16}\cdot 1^{\frac{1}{2}}=\\ \sqrt{16} \cdot1=\\ \sqrt{16} =\\ \boxed{4} Therefore, the correct answer is answer D.

Answer

4 4

Exercise #5

Solve the following exercise:

1โ‹…2= \sqrt{1}\cdot\sqrt{2}=

Video Solution

Step-by-Step Solution

Let's start by recalling how to define a square root as a power:

an=a1n \sqrt[n]{a}=a^{\frac{1}{n}}

Next, we remember that raising 1 to any power always gives us 1, even the half power we got from converting the square root.

In other words:

1โ‹…2=โ†“12โ‹…2=112โ‹…2=1โ‹…2=2 \sqrt{1} \cdot \sqrt{2}= \\ \downarrow\\ \sqrt[2]{1}\cdot \sqrt{2}=\\ 1^{\frac{1}{2}} \cdot\sqrt{2} =\\ 1\cdot\sqrt{2}=\\ \boxed{\sqrt{2}} Therefore, the correct answer is answer a.

Answer

2 \sqrt{2}

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