Constant: d/dx [c]: 0 Power rule: d/dx [xⁿ]: n xⁿ⁻¹ Constant multiple rule: d/dx [c f(x)] = c f'(x) Sum rule: d/dx [f + g] = f' + g' Difference rule: d/dx [f − g] = f' − g' Product rule: d/dx [fg] = f'g + fg' Quotient rule: d/dx [f/g] = (f'g − fg') / g² Chain rule: d/dx [f(g(x))] = f'(g(x)) · g'(x) d/dx [x]: 1 d/dx [x²]: 2x d/dx [x³]: 3x² d/dx [√x]: 1/(2√x) d/dx [1/x]: −1/x² d/dx [eˣ]: eˣ d/dx [aˣ]: aˣ ln a d/dx [ln x]: 1/x d/dx [log_a x]: 1/(x ln a) d/dx [sin x]: cos x d/dx [cos x]: −sin x d/dx [tan x]: sec² x d/dx [cot x]: −csc² x d/dx [sec x]: sec x tan x d/dx [csc x]: −csc x cot x d/dx [arcsin x]: 1/√(1 − x²) d/dx [arccos x]: −1/√(1 − x²) d/dx [arctan x]: 1/(1 + x²) d/dx [sinh x]: cosh x d/dx [cosh x]: sinh x d/dx [e^(2x)]: 2e^(2x) d/dx [sin(3x)]: 3 cos(3x) d/dx [(x² + 1)³]: 6x(x² + 1)² d/dx [x eˣ]: eˣ(x + 1) d/dx [x sin x]: sin x + x cos x d/dx [ln(x²)]: 2/x d/dx [5x⁴ − 3x + 7]: 20x³ − 3 Derivative as slope: The slope of the tangent line at a point Limit definition of derivative: f'(x) = lim (h→0) [f(x + h) − f(x)] / h Second derivative: The derivative of the derivative; tells concavity Critical point: A point where f' = 0 or f' does not exist First derivative test: f' changes from + to − at a local maximum, and − to + at a local minimum Second derivative test: f'' > 0 gives a local minimum; f'' < 0 gives a local maximum Inflection point: A point where concavity changes Concave up: f'' > 0; the graph curves like a cup Concave down: f'' < 0; the graph curves like a cap Velocity from position: v(t) = s'(t) Acceleration from position: a(t) = s''(t) Mean value theorem: A smooth curve has a point where the slope equals the average slope over the interval L'Hôpital's rule: For 0/0 or ∞/∞ forms, lim f/g = lim f'/g' (if that limit exists) Implicit differentiation: Differentiate both sides with respect to x, using dy/dx for y terms Related rates: Differentiate an equation in time to link rates of change Tangent line equation: y − f(a) = f'(a)(x − a) Rolle's theorem: If f(a) = f(b) and f is smooth, there is a point between where f' = 0 Free flashcards from Peabody at peabody.kids/flashcards/math-derivative-rules