Directions: For each question, select the best answer from the four choices. After you choose an answer, the correct solution and explanation will appear immediately below the question — this is a self-study mockup, not a timed scoring tool. A graphing calculator (Desmos) is available via the button above. All 24 questions are the highest-error, most computationally demanding items across AP Precalculus Units 1–4. Work every one without a calculator first when possible, then check your reasoning.