difference quotient

English

Noun

difference quotient (plural difference quotients)

  1. (mathematical analysis) A mathematical quantity of the form f(a+h)−f(a)h for some function f(x), having two main interpretations:
    1. (calculus) The average rate of change of the function f(x) over the interval [a,a+h]. As h approaches zero, the value of f(a+h)−f(a)h approaches the derivative or instantaneous rate of change of f(x) at x=a.
    2. (geometry) The slope of the secant line passing through the points (a,f(a)) and (a+h,f(a+h)). As the horizontal distance h>0 between the points approaches zero, the slope of this secant line approaches the slope of the tangent line to f(x) at x=a, which is equal to the derivative of f(x) at x=a.

Translations

See also