application or intradermal injection of a substance to the skin to test the body's reaction to it. Such a test detects an animal's sensitivity to such allergens as dust and pollen, or to preparations of microorganisms believed to be the cause of a disorder.
A direct relationship graph is a graph where one variable either increases or decreases along with the other. The general equation for a direct relationship graph is y = mx + b, where y denotes the...
The graph of a relation of the form y = 5 is a line parallel to the x-axis because the y value never changes. A line parallel to the x-axis is called a horizontal line. The graph of a relation of the form x = 5 is a line parallel to the y-axis because the x value never changes. A line parallel to the y-axis is called a vertical line. Plot the graph of each of the following relations: horizontal line, vertical line.