I would help you but I can't see it maybe zoom in a little closer.
1)Not a function
2)yes
3)not a function
Answer:
Step-by-step explanation:
abc = 1
We have to prove that,

We take left hand side of the given equation and solve it,

Since, abc = 1,
and c = 
By substituting these values in the expression,




Which equal to the right hand side of the equation.
Hence, 