How do you write intervals of increase and decrease?

As part of exploring how functions change, we can identify intervals over which the function is changing in specific ways. We say that a function is increasing on an interval if the function values increase as the input values increase within that interval. Similarly, a function is decreasing on an interval if the function values decrease as the input values increase over that interval. The average rate of change of an increasing function is positive, and the average rate of change of a decreasing function is negative.

The image below shows examples of increasing and decreasing intervals on a function.

answer: 180

step-by-step explanation:

12-2=10

20-2=18

10x18=180