Answer:
First one: Function
Second one: not a function (a function cannot have two outputs)
Third one: Function
Last one: Not a function (doesn't pass vertical line test)
Step-by-step explanation:
Hope it helps!
Answer:
A and b r the same but b is just under x line
C would be the answer cause if it was d it be under x line
Answer:
A =4πr2
Step-by-step explanation: