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Simplifying The Square Root of A Whole Number Calculator

Reviewed by Calculator Editorial Team

Simplifying square roots is a fundamental math skill that helps you express square roots in their most reduced form. This process involves breaking down the square root of a number into a product of a perfect square and another square root. The simplified form is often easier to work with in further calculations.

What is simplifying square roots?

Simplifying square roots means expressing a square root in its simplest radical form. This involves factoring the number under the square root into perfect squares and other factors. The simplified form typically has a smaller number under the square root sign.

Simplified Square Root Formula

√(a × b) = √a × √b

When a is a perfect square, √(a × b) = √a × √b = n × √b

The process of simplifying square roots is based on the property that the square root of a product is the product of the square roots. This property allows us to break down complex square roots into simpler components.

How to simplify square roots

To simplify a square root of a whole number, follow these steps:

  1. Factor the number under the square root into its prime factors.
  2. Identify pairs of identical prime factors (perfect squares).
  3. Take one factor from each pair out of the square root and multiply them together.
  4. Leave the remaining factors under the square root sign.

Important Note

Only perfect square factors can be taken out of the square root. Numbers that are not perfect squares (like 2, 3, 5, etc.) must remain under the square root sign.

This method works because the square root of a perfect square is an integer, which simplifies the expression.

Examples

Let's look at some examples to see how simplifying square roots works in practice.

Example 1: Simplifying √36

36 is a perfect square (6 × 6), so:

√36 = 6

Example 2: Simplifying √72

Factor 72: 72 = 36 × 2 = 6² × 2

√72 = √(36 × 2) = √36 × √2 = 6√2

Example 3: Simplifying √128

Factor 128: 128 = 64 × 2 = 8² × 2

√128 = √(64 × 2) = √64 × √2 = 8√2

These examples show how to simplify square roots by factoring and identifying perfect squares.

Common mistakes

When simplifying square roots, there are several common mistakes to avoid:

  • Taking non-perfect square factors out of the square root
  • Forgetting to multiply the factors taken out of the square root
  • Incorrectly factoring the number under the square root
  • Not checking if the remaining factors can be simplified further

Tip

Always double-check your factoring and verify that you've taken all possible perfect squares out of the square root.

FAQ

What is the difference between simplifying and rationalizing a square root?

Simplifying a square root involves expressing it in its simplest radical form by factoring out perfect squares. Rationalizing involves eliminating radicals from the denominator of a fraction. These are different processes with different goals.

Can I simplify the square root of a negative number?

No, the square root of a negative number is not a real number. It's an imaginary number, which is expressed using the imaginary unit i (where i² = -1).

What if the number under the square root doesn't have any perfect square factors?

If the number under the square root doesn't have any perfect square factors other than 1, then the square root is already in its simplest form.