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Square Root Calculator Radical+expression

Reviewed by Calculator Editorial Team

This square root calculator helps you find the square root of any number or simplify radical expressions. Whether you're solving math problems, working with geometry, or analyzing data, understanding square roots is essential.

What is a Square Root?

The square root of a number is a value that, when multiplied by itself, gives the original number. For example, the square root of 16 is 4 because 4 × 4 = 16. Square roots are represented by the radical symbol √.

In mathematics, the square root of a number x is written as √x. The principal (or non-negative) square root is the one most commonly used. For example, √9 = 3, not -3, because we typically consider the positive root unless specified otherwise.

Square roots of negative numbers are complex numbers, involving the imaginary unit i (where i² = -1). For example, √-1 = i.

How to Calculate Square Roots

There are several methods to calculate square roots:

  1. Prime Factorization: Break down the number into its prime factors, then pair them and take one from each pair.
  2. Long Division Method: A step-by-step process similar to long division for decimals.
  3. Using a Calculator: The quickest method for most practical purposes.
  4. Estimation: Approximate the square root by finding numbers that, when squared, are close to the original number.

Our square root calculator uses a combination of these methods to provide accurate results quickly.

Radical Expressions

Radical expressions involve square roots and other roots. They can be simplified by:

  • Removing perfect square factors from the radicand (the number under the radical).
  • Combining like radicals (radicals with the same index and radicand).
  • Rationalizing denominators (removing radicals from the denominator).

For example, √18 can be simplified to 3√2 because 18 = 9 × 2 and √9 = 3.

√(a × b) = √a × √b √(a / b) = √a / √b

Examples

Example 1: Simple Square Root

Find √25.

Solution: 25 is a perfect square (5 × 5), so √25 = 5.

Example 2: Radical Expression

Simplify √72.

Solution: Factor 72 into 36 × 2, then √72 = √(36 × 2) = √36 × √2 = 6√2.

Example 3: Decimal Square Root

Find √2.25.

Solution: 1.5 × 1.5 = 2.25, so √2.25 = 1.5.

FAQ

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

A square of a number is the result of multiplying the number by itself (e.g., 5² = 25). A square root is a number that, when multiplied by itself, gives the original number (e.g., √25 = 5).

Can I find the square root of a negative number?

Yes, but the result will be an imaginary number involving the imaginary unit i. For example, √-1 = i.

How do I simplify a radical expression?

To simplify √a, factor a into perfect squares and take one from each pair. For example, √50 = √(25 × 2) = 5√2.