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 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-√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 52 = 25.
So -√25 = -√52.
Cancel the square root and the square.
Then -√52 = -5.
So -5 is the answer.