Question

Let f be the subset of N x N defined by f={(ab,a+b): a,b∈N}
Is f a function from N to N?
Is f of a relation from N to N? Justify your answer.​

Answer 1

Answer:

f is not a function

reason

let a=1 and b=6

then (6,7) belongs to f

now, let a=2 and b=3, then (6,5) belongs to f

it means element 6 have more than 1 image.

Therefore f is not a function.

f is a relation as f is a subset of N X N.