Its is a function. mentally connect the dots. run your pencil across the paper parallel to the y-axis. if none of the points have touch the pencil it is a function. another way to check. look at the X value of all the coordinates. if they are all different its a function.
Answer:
You either wrote it down wrong, or there's a graphic to go along with it that you didn't include. There is not enough information to answer this question, sorry.
That is true because as you can see in the other 2 equations, they both have z on one of the sides meaning that the sides that don't have z are equal to each other
Hope this helps :)
