TMUA-P2-PRF5-003 — Paper P2 · Following proofs · Level 2

Options

1. A
   Prove only: if $n$ is even then $n^2$ is even.
2. B
   Prove only: if $n^2$ is even then $n$ is even.
3. C
   Prove both directions: ($\Rightarrow$) $n$ even gives $n^2$ even, and ($\Leftarrow$) $n^2$ even gives $n$ even (e.g. via contrapositive).
4. D
   Give one example, e.g. $n = 4$.
5. E
   Prove: if $n$ is odd then $n^2$ is even.

Letters only — the answer key is hidden. Work it out, then check the solution below.

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