What is the square root of 81?
Understand the Problem
The question is asking for the square root of the number 81, which is a basic arithmetic operation.
Answer
9
Answer for screen readers
The final answer is 9
Steps to Solve
- Identify the operation to be performed
The operation required is to find the square root of the number 81.
- Recall the definition of a square root
The square root of a number $x$ is a number $y$ such that $y^2 = x$.
- Find the appropriate value
We need to find a number which, when multiplied by itself, equals 81. We can check integer values:
$$9 imes 9 = 81$$
So, the square root of 81 is 9.
The final answer is 9
More Information
When dealing with square roots, it's essential to recognize that every positive real number has two square roots: a positive and a negative one. In this case, both 9 and -9 are square roots of 81, but typically, the principal (positive) square root is considered when the context doesn't specify otherwise.
Tips
A common mistake is to forget that the square root operation yields both a positive and a negative number. For example, both 9 and -9 are valid square roots of 81 because $(-9) \times (-9) = 81$ and $9 \times 9 = 81$.
