# Square Root

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

## Example√9

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

Square

Solution

Solution (Detail)

Change the number in the radical sign,

9,

to a perfect square.

Think of a positive number

whose square is 9.

3 is good

because 3^{2} = 9.

So √9 = √3^{2}.

Cancel the square root and the square.

Then √3^{2} = 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-√25

Solution

Solution (Detail)

Change the number in the radical sign,

25,

to a perfect square.

Think of a positive number

whose square is 25.

5 is good

because 5^{2} = 25.

So -√25 = -√5^{2}.

Cancel the square root and the square.

Then -√5^{2} = -5.

So -5 is the answer.