TMUA-P2Y-PRF-008 — Paper P2 · Direct proof · Level 2

Options

1. A
   $4k^2$ is large, so it must be a multiple of $4$.
2. B
   Checking $n = 2$ gives $4$, so the claim holds for all $n$.
3. C
   Since $n^2$ is even, it is automatically a multiple of $4$.
4. D
   Since $k^2$ is an integer, $n^2 = 4(k^2)$ is $4$ times an integer, which is exactly the definition of a multiple of $4$.

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

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