Every problem shows a student's worked solution with exactly one mistake hidden inside. Read carefully, click the wrong step, and explain why it fails.
Requires: Limits QuestRequires: Derivatives Quest
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Read carefully
Each solution has exactly one wrong step. The final answer may even look right.
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Click the bad step
No multiple choice — you have to find the error yourself by clicking the step.
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Understand why
Finding the step is only half the challenge. The explanation reveals the flawed thinking.