## How do you know if the graph is a function?

Inspect the graph to see if any vertical line drawn would intersect the curve more than once.

If there is any such line, the graph does not represent a function.

If no vertical line can intersect the curve more than once, the graph does represent a function..

## How do you know if it is a function or not?

A WAY easier (and faster), way to know if it is a function is to see if there are two of the same x-intercept (which make a vertical line). If there is, then it is NOT a function.

## What is a function rule for a graph?

A function is a relation where there is only one output for every input. In other words, for every value of x, there is only one value for y. Function Rule. A function rule describes how to convert an input value (x) into an output value (y) for a given function. An example of a function rule is f(x) = x^2 + 3.

## How do you know if a function is one to on?

An easy way to determine whether a function is a one-to-one function is to use the horizontal line test on the graph of the function. To do this, draw horizontal lines through the graph. If any horizontal line intersects the graph more than once, then the graph does not represent a one-to-one function.

## What is a function and not a function?

A function is a relation in which each input has only one output. : y is a function of x, x is not a function of y (y = 9 has multiple outputs). … : y is not a function of x (x = 1 has multiple outputs), x is not a function of y (y = 2 has multiple outputs).

## What does a function graph look like?

The graph of a function f is the set of all points in the plane of the form (x, f(x)). We could also define the graph of f to be the graph of the equation y = f(x). So, the graph of a function if a special case of the graph of an equation.