Question

Show that the function f:N defined by f(x) = 2x is one one function but not onto function???

Answer 1

Answer:

Given f:N defined by f(x) = 2x

Let x1,x2 such that

f(x1) = f(x2)

x1 = x2

So by reading it's definition f is one one function.

For checking onto = 2x=3

= x = 3/2 ≠ N

So f is not onto function.