This process doesn't have to be 'algebraic' it is just 'clear' (or 'rigorous') (more so than looking at a picture at least). A visual test that determines whether a curve is a function or not by examining the number of y y y -values associated with each x x x. $f(x) = x^2$ is another function, to check this is a function amounts to just checking that when you take any number x and square it, the output is unique (there is a single output, for example, -3 gets sent to the unique output $(-3)^2 = 9$) In this way, $x^2$ is a function. Let's say our 'relation' is f(x) = x (so the 'identity function', sends numbers to themselves), we start with a number a, and f sends this a to f(a), which is just a in this case, so we start with a, and this a gets sent just to a, so where the function sends any number a (to itself) is definitely unique. This time you draw a horizontal line, and if the line touches the original function in more. In order to be a function, each x value can. The horizontal line test works similar to the vertical line test. Then choose your answers from the pull-down menues. Watch popular content from the following creators: kat(talkcleantome), Math Videos with Sir. Instead of looking at a mapping diagram, though, we will look at a graph. Look carefully at the graphs, and think about what the Vertical Line Test tells you. Discover short videos related to vertical line test on TikTok. In practice, this typically amounts to checking how the 'relation' is defined, and comparing it with this 'exactly one' condition. The Vertical Line Test is a visual test that you can use to quickly check and see if a graph represents a function. The vertical line test is another way to determine if a relation is a function.

To say that a 'relation' (or oftentimes 'graph') is a 'function' from A to B (A is the domain and B is the range) is to say that for any number a (in A) (so any number we take a 'y value' at), there is exactly one number that this a gets mapped to. A vertical line test is a visual way to determine if the graph of a relation is a function using a vertical line.

Vertical line test