Rate of Change and Function Behavior
The rate of change (ROC) tells us how quickly a function's output changes compared to its input. We calculate it using the formula: ROC = y2−y1/x2−x1. This is essentially the slope of a line between two points.
Different functions have different ROC patterns. For linear functions, ROC is constant. For quadratic functions, ROC changes linearly. Understanding these patterns helps you identify function types from data.
When analyzing graphs, remember that positive ROC means the function is increasing, while negative ROC means it's decreasing. The concavity matters too—concave up shows an increasing rate of change, while concave down shows a decreasing rate.
Quick Tip: To find a polynomial's degree from a table of values, count how many times you need to take differences until you get a constant value. For example, if you need to take differences twice, it's a quadratic (degree 2).
Polynomials have special properties worth noting. The degree tells you the maximum number of zeros x−intercepts possible. Even multiplicity zeros like(x−2)2 create tangent points with the x-axis, while odd multiplicity zeros like(x−2) cross through the axis.