Square Root

How to solve the square root of a number: 2 examples and their solutions.

Example 1

Example

Square root [√ ], is the opposite operation of square [ 2].

Square

Solution

Change the number inside the radical sign, 9, to a perfect square.
Think of a positive number whose square is 9.
3 is good because 32 = 9.
So √9 = √32.

Cancel the square root and the square.
Then √32 = 3.

Square root and square are the opposite operations: just like (+) and (-).
So you can cancel the square root and the square like this.

So 3 is the answer.

Example 2

Example

Solution

Change the number inside the radical sign, 25, to a perfect square.
Think of a positive number whose square is 25.
5 is good because 52 = 25.
So -√25 = -√52.

Cancel the square root and the square.
Then -√52 = -5.

So -5 is the answer.