Stage 36 · Limits, Derivatives & Their Applications
36.3.3 Finding the Equation of a Tangent
36.3 What a Derivative Really Is: Concept and Geometry
Point 3 of 5
36.3.3 Finding the Equation of a Tangent
Core ideaOnce you know the point of contact and the slope f′(x₀), the point-slope form hands you the tangent in one step.
Module goal. Promote the derivative from "a number at one point" to "a brand-new function," and nail down its geometric meaning once and for all: the slope of the tangent.