Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The average rate of change refers to the average rate at which a quantity changes over a given interval. It is calculated by finding the slope of the secant line between two points on a graph.
The instantaneous rate of change represents the rate at which a quantity is changing at a specific point or instant. It is found by calculating the slope of the tangent line to that point on a graph.
Secant line: A secant line is a straight line that intersects two points on a curve. It can be used to calculate the average rate of change between those two points.
Slope measures how steep or flat a line is. It indicates how much y changes for every unit increase in x and can be used to find both average and instantaneous rates of change.