Question

For each problem below, either give an example of a function satisfying the give conditions, or...

For each problem below, either give an example of a function satisfying the give conditions, or explain why no such function exists.

(a) An injective function f:{1,2,3,4,5}→{1,2,3,4}

(b) A surjective function f:{1,2,3,4,5}→{1,2,3,4}

(c) A bijection f:N→E, where E is the set of all positive even integers

(d) A function f:N→E that is surjective but not injective

(e) A function f:N→E that is injective but not surjective

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