## Precalculus (6th Edition) Blitzer

(a) The $y$ -coordinate is 3 when the $x$ -coordinate is 2. (b) The $x$ -coordinates are $-3\text{ and }3$ when the $y$ -coordinate is 4. (c) Consider the provided graph, To describe the $x$ -coordinates of all the points on the graph, analyses the points on the graph. The $x$ -coordinates of all the points on the graph are either positive, negative or zero value which is the all real numbers. A real number is a number that can be found on the number line. These are the numbers that we normally use and apply in real-world applications. Hence, the $x$ -coordinates are all real numbers. (d) Consider the provided graph. To describe the $y$ -coordinates of all the points on the graph, analyze the points on the graph. The $y$ -coordinates of all the points on the graph are all positive numbers starting with 1; zero is not one of the points of the $y$ -coordinates because the graph starts with 1. So, the $y$ -coordinates are all real numbers greater than or equal to 1. A real number is a number that can be found on the number line. These are the numbers that we normally use and apply in real-world applications. Hence, the $y$ -coordinates are all real numbers greater than or equal to 1.