Question

f:N →N: f(x) = 2x is A. one - one and onto B. one - one and into C. many - one and onto D. many - one and into​

Answer 1

Answer:

f:N →N: f(x) = 2x is A. one - one and onto B. one - one and into C. many - one and onto D. many - one and into​

Step-by-step explanation:

Answer 2

The function is surjective (onto) if every element of the codomain is mapped to by at least one element of the domain.

f(x)=2x 

Domain of f is N 

Codomain of f is N

Every element of N(codomain) is mapped to only one element in N(domain)

i.e. f(x)=f(y)

⟹2x=2y⟹x=y

Hence f is one one function

Every even element of N(codomain) has corresponding value in N(domain).

But, for any odd number in N(codomain) has no corresponding value in Ndomain.

Hence, f is not onto function.