This week we learned about functions. Functions are related to domain and range because they are what make it up (relates them through an equation). You use it by using the replacement for x and y in equations to find the opposite. It can be tricky though to spot this special type of relation because each element of the domain is related to exactly one element of the range, which can be hard to spot sometimes. Im going to show you all the methods you can use to spot what relations are real functions. First you can see using an arrow diagram, the rule is if more than one arrow leaving an input number to an output means it is not a function, then ordered pairs, if the input value (x,y) shows up more than once in your sequence then it isn’t a function, and lastly in graphs you can find out whether it is a function by using the vertical line method, using this method you can find a “fake” function by seeing if any vertical line drawn on the graph intersects more than once on the graph then it is not a function. Down below I have shown you examples of spotted non-functions and real ones.