Question

which is a function? {(8,9),(−2,9),(7,5),(−4,−7)} {(−5,−7),(−5,4),(−2,−8),(3,5)} {(8,0),(−4,−2),(7,1),(0,0)} {(−8,3),(−5,−7),(−4,5),(9,3)}

Answer 1

All but the second

{(8,9),(−2,9),(7,5),(−4,−7)}

{(8,0),(−4,−2),(7,1),(0,0)}

{(−8,3),(−5,−7),(−4,5),(9,3)}

Explanation:

Function means that for each x we get y, and no no x gives two different y-es

{(−5,−7),(−5,4),(−2,−8),(3,5)} for x = -5 we have two different y-es therefore its not function