Final answer:
The point where number lines intersect is known as the origin, which serves as the starting point in a coordinate system with the coordinates (0, 0).
The y-intercept is the point where a plot line crosses the y-axis, and in other contexts, like economics, intersections such as between supply and demand curves can define concepts like equilibrium.
Step-by-step explanation:
The origin has coordinates (0, 0) and acts as the starting point for measuring distance and direction on both axes.
When discussing graphing in a coordinate plane, another important concept is the y-intercept, which is the point where a graph or plot line intersects with the y-axis. The y-intercept is important for understanding linear relationships, as it tells us the value of y when x is zero.
In different contexts, intersections can have specific meanings beyond the simple geometric one.
For example, in economics, the point where the supply curve (S) and the demand curve (D) intersect is called the equilibrium. This particular intersection signifies a state where the quantity of goods consumers want to buy is equal to the amount producers want to sell, establishing the equilibrium price.