Chapter 1
Linear Equations and Graphing
Course: Gre
Subject: Gre Quantitative Reasoning
Chapter: Foundations Of Functions And Composition
Introduction: The Inverse of Squaring
Squaring a number and taking its square root are inverse operations. If a square has side length s, its area is s². If a square has area A, its side length is √A. This lesson explores square roots, their properties, and how to work with them.
What Is a Square Root?
A square root of a number x is a number r such that r² = x.
The Square Root Sign
√x
This symbol is called a radical. The number inside is the radicand.
Examples
| Equation | Meaning | | √25 = 5 | 5² = 25 | | √16 = 4 | 4² = 16 | | √9 = 3 | 3² = 9 |
Principal Square Root
Every positive number has two square roots: a positive one and a negative one.