Скачать или смотреть Calculus 1 — 5.2: The Tangent Problem

How do you find the slope of a curve at a single point when the slope formula requires two points? This video walks through the tangent problem — the paradox that launched calculus — showing how secant lines, sliding closer and closer to a target point, reveal the tangent slope through the concept of a limit.

Key concepts covered:
• Why slope at a single point seems impossible (one point vs. the two-point slope formula)
• Secant lines vs. tangent lines — definitions and Latin origins (secare = to cut, tangere = to touch)
• Computing secant slopes as approximations of the tangent slope
• Sliding point Q toward point P and watching secant slopes converge
• Why setting Q equal to P produces 0/0 (undefined), not an answer
• The distinction between 0/5, 5/0, and 0/0
• The limit: asking what value slopes approach rather than what happens at the point
• Numerical example with f(x) = x² at x = 1, showing secant slopes converging to exactly 2
• How the limit concept becomes the foundation of the derivative

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SOURCE MATERIALS
The source materials for this video are from    • Calculus 1 Lecture 1.1:  An Introduction t...