# Square Root

The square root is a mathematical operation that calculates the value that, when multiplied by itself, gives a certain number. It is represented by the symbol √ and is a fundamental concept in mathematics. The square root is used in a variety of mathematical applications, including geometry, algebra, and trigonometry.

## Calculating Square Roots

To calculate the square root of a number, you can use a calculator or do it manually. Here’s how to do it manually:

1. Estimate: Make an estimate of the square root by finding the closest perfect square to the number you want to take the square root of. For example, to find the square root of 27, you can estimate that it is between 5 and 6, because 5^2 = 25 and 6^2 = 36.
2. Divide and Average: Divide the number you want to find the square root of by the estimate you made in step 1. Then, average the result with the estimate from step 1. Repeat this process until you get a sufficiently accurate answer. Here’s an example:

## To find the square root of 27:

• Estimate: 5
• Divide: 27 / 5 = 5.4
• Average: (5 + 5.4) / 2 = 5.2
• Divide: 27 / 5.2 = 5.192
• Average: (5.2 + 5.192) / 2 = 5.196

Continue this process until you reach the desired level of accuracy.

## Using the Square Root

Once you have calculated the square root of a number, you can use it in a variety of mathematical applications. For example, the Pythagorean theorem in geometry involves finding the square root of the sum of the squares of the sides of a right triangle. In algebra, the square root is used to solve quadratic equations, which are equations of the form ax^2 + bx + c = 0. The square root is also used in trigonometry to find the lengths of sides and angles in triangles.

## Practice Exercise

Now that you have learned about the square root in mathematics, let’s try a practice exercise.

1. √16
2. √25
3. √42
4. √81
5. √2