TMUA-P2-ERR2-017 — Paper P2 · Common fallacies · Level 2

Options

1. A
   The equation $\sin A=\sin B$ holds when $A=B+2k\pi$ or $A=\pi-B+2k\pi$; here $\theta=0,\pi,\pi/3,5\pi/3$, so most solutions were lost by equating angles.
2. B
   $\theta=0$ is indeed the complete solution set.
3. C
   There are no solutions in $[0,2\pi)$.
4. D
   $\theta=\pi/2$ is the only solution.

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

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