Skip to content
World 1 · Functions & Limits · 7 min

Average rate of change

The secant line

Teaching this? Open projector mode

Between two points on a curve, the average rate of change is just the slope of the straight line joining them — the secant. It answers "on average, how fast did the output change across this interval?"

Formula: (f(b) − f(a)) / (b − a). It is rise over run again, now for a curve. On a distance-vs-time graph this average rate is your average speed over the trip.

Check yourself

The average rate of change of f on [a,b] is…

0 of 1 required activities complete. Finish each task and quiz.Next lesson →

Report a mistake

What is wrong?
0 / 2000 · at least 10 characters
Sent along with your report
  • Page
  • About Average rate of change — Calculus & Probability · calcprob/fl7-average-rate-of-change
Plus your browser type. Reports go to our support system; see the privacy notice.