Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
A perfect square is a number that can be expressed as the product of two equal integers. In other words, it is a number that is the square of some integer. These numbers have a unique property of having an even number of factors.
5 Must Know Facts For Your Next Test
The first few perfect squares are: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100.
Any number that is a perfect square has an even number of positive divisors.
The square root of a perfect square is always a whole number.
Identifying and extracting perfect squares is a key step in simplifying radical expressions.
Perfect squares play a crucial role in the topic of 8.1 Simplifying Expressions with Roots, as they help reduce the complexity of radical expressions.
Review Questions
Explain how the concept of perfect squares is related to simplifying radical expressions.
In the context of 8.1 Simplifying Expressions with Roots, the concept of perfect squares is crucial. When simplifying radical expressions, one of the key steps is to identify and extract any perfect squares within the radicand. This allows the expression to be rewritten in a simpler form by taking the square root of the perfect square outside the radical. By recognizing and isolating perfect squares, the complexity of the radical expression can be reduced, making it easier to evaluate and work with.
Describe the relationship between perfect squares and the number of factors a number has.
Perfect squares have a unique property in that they have an even number of positive divisors or factors. This is because a perfect square can be expressed as the product of two equal integers. For example, the number 16 is a perfect square because it can be written as 4 ร 4. As a result, the positive factors of 16 are 1, 2, 4, 8, and 16 - an even number of factors. This relationship between perfect squares and the number of factors is an important concept that can be applied when simplifying expressions involving roots and squares.
Analyze how the square root of a perfect square can be used to simplify radical expressions.
$$\begin{align*} \text{When simplifying radical expressions in the context of 8.1 Simplifying Expressions with Roots,} \\ \text{the square root of a perfect square plays a crucial role.} \\ \text{If a radicand contains a perfect square, it can be rewritten as the product of the square root of} \\ \text{the perfect square and the remaining factor under the radical.} \\ \text{This allows the expression to be simplified by taking the square root of the perfect square} \\ \text{outside the radical, reducing the complexity of the expression.} \\ \text{Understanding the properties of perfect squares and their square roots is essential} \\ \text{for effectively simplifying radical expressions.} \end{align*}$$
The square root of a number is the value that, when multiplied by itself, gives the original number. For example, the square root of 9 is 3, because 3 ร 3 = 9.
Irrational numbers are numbers that cannot be expressed as a simple fraction, and their decimal representation neither terminates nor repeats. The square roots of non-perfect squares are irrational numbers.
A radical expression is a mathematical expression that contains a square root symbol. Simplifying radical expressions often involves identifying and extracting perfect squares.