Vertical Line Test
Definition Of Vertical Line Test
Vertical Line Test is a test used to determine whether a relation is a function or not. A graph is said to be a function if the vertical line drawn does not intersect the graph more than one point.
More About Vertical Line Test
Vertical line test is generally done by using a ruler. A vertical line is drawn across the edge of the ruler from one end of the x-axis to the other end.
Examples of Vertical Line Test
Using vertical line test, the graph given represents a function as the vertical line drawn intersects the graph at only one point.
Video Examples: Vertical Line Test
Using vertical line test, the graph given does not represent a function as the Vertical line drawn intersects the graph at more than one point
Solved Example on Vertical Line Test
Ques: Identify the graph that represents a function by using the vertical line test.
Choices:
A. Graph 4
B. Graph 2
C. Graph 3
D. Graph 1
Correct Answer: D
Solution:
Step 1: A graph represents a function if no vertical line intersects the graph more than once. [Vertical Line Test.]
Step 2: For the Graphs 2, 3 and 4, it is possible to draw a vertical line that intersects the graph in two points as shown below
Step 4: So, Graph 2, Graph 3 and Graph 4 do not represent a function
Step 5: No vertical line can intersect the Graph 1 more than once
Step 6: So, Graph 1 represents a function.