The beauty of Passwater’s work is the built-in feedback loop . Because the "answers" are technically provided on the page (they just aren't labeled), you don't need an external answer key. If you solve a problem and the answer isn't a "header" for another box, you need to: Check your algebraic steps. Verify your unit circle values. Re-read the graph or table provided. How to Find Help Without Cheating
If you are a student using this article, ask yourself: Am I looking for the answer to check my work, or to avoid doing my work? If it’s the latter, you will fail the AP exam in May. The exam does not have a "Bryan Passwater answer key."