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Code Scholars Tutoring · AP Calculus BC

Unit 2: Differentiation: Definition and Fundamental Properties

10 topics across 4 lessons, with explanations, worked examples, and self-checks that develop complete mathematical reasoning.

Topics 2.1, 2.2, 2.3

Derivatives as limits and local rates

The derivative is the limit of secant slopes when that limit exists. It is both the slope of the tangent and an instantaneous rate with output-units per input-unit. Estimate from nearby table entries; a symmetric secant is often useful but still approximate. Distinguish a derivative value at one point from a derivative function on a domain.

Topics 2.4

Where derivatives fail to exist

Differentiability at a point implies continuity there; the converse fails. Corners have different one-sided slopes, cusps may have unbounded one-sided slopes, and vertical tangents have no finite derivative. Discontinuities automatically prevent differentiability. For a piecewise function first enforce continuity, then compare the limiting derivative from each side.

Topics 2.8, 2.9

Product and quotient rules

A product derivative differentiates one factor at a time and adds the two terms. For a quotient, multiply the denominator by the numerator derivative, subtract numerator times denominator derivative, and divide by the denominator squared. Simplification before differentiating may shorten the work. A derivative formula is valid only where the original function and relevant derivatives exist.

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