Continuity vs. Differentiability

A function is differentiable at a point only if the slopes from both sides match; sharp corners and vertical tangents are the two main cases where derivatives fail to exist.


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Feynman technique

Learn with the Feynman Technique

Explain each idea in your own words in handwriting, then upload a photo for AI critique. Two attempts per question — there's no "right" answer, only depth of understanding.