The vertical line test is one of the simplest ways a graphing question will be used on the SAT. It is important to know that f(x) means y. When graphing, the f(x) value will be the same as the y value.  

 

Domain and range are also important for graphing question on the SAT. To find the domain on a graph, it is simply a matter of finding the highest X value and the lowest X value. Everything in between (and including) those two values is the domain.