A. Write F if the following is a function N if not. _____1. {(1,3),(4,2),(6,8)} _____2. {(2,2),(4,3),(5,6),(7,9),(10,10)} _____3. {(1,2),(1,3),(2,4),(1,6)} _____4. {(1,3),(2,4),(3,5),(4,6)} _____5. {(1,1),(9,3),(9,-3),(0,0)}