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High School Mathematics - 2
4.1 Test of Functions: Vertical Line Test

The vertical line test
One way to tell if a graph is a function is the vertical line test, which states that if it is possible for a vertical line to meet a graph more than once, the graph is not a function.

Method to test a function:
Draw a line parallel to the y-axis. If this line cuts the graph at one distinct point, then it is a function otherwise it is not a function.

Q 1: A vertical line with x-intercept a has an equation of the form x = a. Is this line a function.

Q 2: If each input has exactly one output then the relation is a function.

Q 3: The vertical line test is a check to see if a graph of a relation is a ________.

Q 4: A graph x = y2 is a function.

Q 5: You can use one of the following to perform a vertical line test.

Q 6: If every vertical line intersect a graph in no more than one point, then the graph is the graph of a function.

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Question 8: This question is available to subscribers only!

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