TMUA-P2-ERR1-012 — Paper P2 · Identifying errors in proofs · Level 2

Options

1. A
   Line (1): it assumes what should be concluded (that $n$ is odd) instead of assuming $n^2$ is odd — the argument proves the converse.
2. B
   Line (2): the expansion of $(2k+1)^2$ is computed incorrectly.
3. C
   Line (3): a number of the form $2m+1$ need not be odd.
4. D
   There is no fault; the proof is valid.

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

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