To rotate a point around the origin by 180 degrees, multiply both parts of the coordinate point by 
. (This means you go from 
to 
.)
Answer:
The 1st and 2nd graph are functions while the 3rd and 4th aren't.
Step-by-step explanation:
The first and second graph doesn't have more than one output for each input. The third and fourth graph isn't a function since there's more than one output for the same input given. If you do the vertical line test, then you'll know which one is a function and which one is not a function. Hope this helps :)
