2019 AMC 12A – Reflection Log
Quick notes on misses, themes, and time sinks.
Incorrect
- #22. Problem and Solutions
- #24. Found all prime exceptions but missed 4 — Problem and Solutions
- #25. Got after hint → need work on angle chasing in cyclic quadrilaterals — Problem and Solutions
Correct
Problems solved:
#15
#16
#17
#18
#19
#20
#21
#23
- #17 → learn Newton's Sums
- #23 → algebra took a long time.
Next Steps
- Drill Newton’s Sums identities; derive first 3–4 power sums using Vieta.
- Re-check prime-exception logic; include 2 and 4 in prime-exception checklist.
- Daily 10-min cyclic quadrilateral angle-chasing (use Ptolemy, equal angles, arc marks).
- Practice pacing to avoid #17-style time sinks; enforce a 2-minute “move on” rule.
- Algebra endurance reps (substitution, factoring patterns), especially for de-jangling #23-type problems.
