Question

Which option is a function

Answer 1

(x,y)
for every x there is exatly 1 y
basically, x never repeats with a differnt y

first one works, no x's repeart

2nd is not, 1 repeats wwth 9 and -4

3rd is correct

4th is wrong, 0 repreats with 3 and 7

5th is correct



so the functions are 1st 3rd 5th