The square root of a non-negative real number is written as , such that
Since , the square root of 9 is .
When we write the square root of a number, we are usually providing both the positive square root amd the negative square root. This is because a negative number squared is a positive number.
1. (9 decimal places)
(1 decimal place)
(2 decimal places)
(3 decimal places)
2. (1 significant figure)
(2 significant figures)
(3 significant figures)
The cube root of A is written as .
Since the cube of 2 is , we say
We can use a calculator to find the square root or cube root of a number. For non-perfect square numbers, the square numbers, the square roots can be given correct to a certain number of decimal places, or correct to a certain number of significant figures. The problem will state the accuracy to be given for the answer.