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Taking The Square Root Calculator

Reviewed by Calculator Editorial Team

Finding the square root of a number is a fundamental mathematical operation with applications in geometry, algebra, and many other fields. This guide explains how to calculate square roots, understand the formula, and interpret results.

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 roots of 9 are 3 and -3 because 3 × 3 = 9 and (-3) × (-3) = 9.

Square roots are important in many areas of mathematics and science. In geometry, they help find the length of a side of a square when the area is known. In algebra, they're used to solve quadratic equations. In physics, they appear in calculations involving velocity and acceleration.

How to calculate square roots

There are several methods to find square roots:

  1. Prime factorization method: Break down the number into prime factors, then pair them and take one from each pair.
  2. Long division method: A more precise method that works for non-perfect squares.
  3. Using a calculator: The quickest method for most practical purposes.

For most practical purposes, using a calculator is the most efficient method. Our square root calculator provides an accurate and convenient way to find square roots without manual calculations.

Square root formula

The square root of a number x can be represented as:

√x = y

where y × y = x

For positive real numbers, there are two square roots: a positive root and a negative root. The principal (or positive) square root is typically used in most contexts.

Examples of square roots

Here are some examples of square roots:

  • √9 = 3
  • √16 = 4
  • √25 = 5
  • √2 = 1.414213562...
  • √0.25 = 0.5

Notice that for perfect squares (numbers that are squares of integers), the square root is an exact integer. For other numbers, the square root is an irrational number that cannot be expressed as a simple fraction.

Frequently Asked Questions

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

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

Can negative numbers have square roots?

Yes, negative numbers can have square roots, but they are complex numbers. For example, √-1 = i, where i is the imaginary unit.

Is the square root of a number always positive?

By convention, the principal (or positive) square root is always positive. However, every positive number has two square roots: one positive and one negative.

What is the square root of zero?

The square root of zero is zero, because 0 × 0 = 0.