## Wednesday, September 23, 2009

### Period 4 Scribe: AROC & Secants

Hi class!

Today we learned about AROC, which is an acronym for Average Rates of Change. This comes from the physics equation of Average Velocity which calculates "change in distance/change in time" which means delta "d" over delta "t". Delta means "change in" so an example would be two different distances of 2 m and 10 m. 2 m would represent d1, and 10 m would represent d2. Now that covers the distance. For time, lets say t1 is 2 seconds, and t2 is 4 seconds. Now since delta means "change in", the equation with the variables plugged in will look like this (d2-d1)/(t2-t1) -> (10m-2m)/(4s-2s). The final answer will be 4 m/s.

AROC is essentially the same. It uses the same delta d over delta t equation to find the average rate of change. On a distance-time graph, we can get our average rate of change by using the slope of a secant. This means that on a graph, we draw a straight line that passes at least 2 different points on a curve. We start at (0,0) and we end at the endpoint. This represents our secant and with this, we can use it for average velocity calculations.

J.