Factors & Multiples – Square And Cube Roots

Posted by: Jas on: May 10, 2009

• In: Factors & Multiples | Maths
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Hmmm, I don’t think THAT particular square root has any purpose…

Right. Now that you have learnt how to perform prime factorization, we shall transfer this skill and apply it on finding square and cube roots.

The idea is very simple. When a number is squared, you are basically multiplying the number by itself, i.e.

Do take note that the brackets involved in the sum are important, as there is a difference between

and

When you are finding the square root of a number, you are basically splitting the number into 2 equal groups (note: this is NOT the same as dividing the number by 2!).

Follow the step-by-step instruction to finding square roots:

E.g. Find the square root of 36.

Step 1: Perform prime factorization on the number of which the square root needs to be found.

Step 2: Express the number as a product of its prime factors.

Step 3: Split the prime factors into 2 equal groups.

Therefore, the square root of 36 is 6.

This idea is similar for finding cube roots as well, except you need to split the prime factors into 3 equal groups:

Do take note that you can have negative answers for cube roots of numbers, as shown in the example below:

Tags: cube roots, prime factorization, square roots