SEAMO 2027 - Paper E - SET 03 - Self-study Question 16

Let $\alpha,\beta$ be acute angles satisfying $\sin\alpha=2021\cos(\alpha+\beta)\sin\beta$. Find the maximum value of $\tan\alpha$.

Source-key warning: the printed key conflicts with the equation as printed. Solve the displayed equation, retaining its plus sign and the original options; the discrepancy is explained after answering.