The Vertical Line Test for Functions: If any vertical line intercepts a graph in more than one point, the graph does not define y as a function of x. By the definition of a function, for each value of x we can have at most one value for y.
"y = f(x) is a function if it passes the vertical line test. It is a 1-1 function if it passes both the vertical line test and the horizontal line test. " - In order to be a one-to-one function, it first has to BE a function and pass the vertical line test. For example, a relation on a graph like a circle that does not pass the vertical line test is not function nor one-to-one.
A vertical test line is useful because, by definition, a function has one and only one result value for each input value. If you can find a vertical line that intersects the curve of the line, then it is not a function. A simple example is a circle.
Many to one function
Y = X2 ===== The graph of this parabola is crossed only at a point and once by a vertical line, so it is a function. Passes the vertical line test.
Absolute value |-5| = 5
The Vertical Line Test for Functions: If any vertical line intercepts a graph in more than one point, the graph does not define y as a function of x. By the definition of a function, for each value of x we can have at most one value for y.
A vertical line. Remember that one test to see if a relation is a function is the vertical line test. A vertical line would fail that of course.
A vertical line can be used to test whether or not a graph is a function.
"y = f(x) is a function if it passes the vertical line test. It is a 1-1 function if it passes both the vertical line test and the horizontal line test. " - In order to be a one-to-one function, it first has to BE a function and pass the vertical line test. For example, a relation on a graph like a circle that does not pass the vertical line test is not function nor one-to-one.
a line that goes up and down
Vertical
Not quite. You can use a vertical line test on the graph of the inverse mapping, OR you can use a horizontal line test on the original graph. The horizontal line test is used in the same way.
No. Because a vertical line will pass through two points on the graph.
Test it by the vertical line test. That is, if a vertical line passes through the two points of the graph, this graph is not the graph of a function.
Three vertical lines, |, with a diagonal line across them.
f(x) = x2 This is a function by the vertical line test because a vertical line drawn through this function will only intersect the function at one point