Chapter 4.3, Problem 9E

(a)

To determine

The range of $f:N\backslash \left\{1\right\}\to N$ by setting $f(n)$ equal to the largest prime divisor of n.

(b)

To determine

If $f:N\backslash \left\{1\right\}\to N$ by setting $f(n)$ equal to the largest prime divisor of n is one-to-one.

(c)

To determine

If $f:N\backslash \left\{1\right\}\to N$ by setting $f(n)$ equal to the largest prime divisor of n is onto.

(d)

To determine

Why did we not express f as a function $N\to N$.