Chapter 3 Section 3 Rate of Change & Slope

Objectives: 1. Find the rates of change and slopes 2. Relate a constant rate of change to the slope of a line.

Vocabulary

·  Rate of Change: ratio that compares the amount of change in the dependent variable to the amount of change in the independent variable

Change in y change in DEPENDENT variable

Change in x change in INDEPENDENT variable

·  Rise: difference in y values w/2 points on a line

·  Run: difference in x values w/2 points on a line

·  Slope Change in y RISE up/down

Change in x RUN left/right

VIDEO #1: Mr. Rutherford. MOVIES: Use the table to find the rate of change. Then explain its meaning.

# of tickets / Total Cost
X / Y
3 / $22.50
6 / $45.00
9 / $67.50

VIDEO #2: Mr. Hardesty: The graph shows the density of population for the state of Idaho in various years.

a.  Find the rates of change for 1930-1960 & 1990 – 2000.

SLOPE =

1930- 1960 =

m =

1990 – 2000 =

b.  Explain the meaning of the slope in each case.

c.  How are the different rates of change shown on the graph?

VIDEO #3: Mrs. Dawson. Determine whether each function is linear. Explain

X / Y / X / Y
-2 / 2 / 0 / 1
-1 / 7 / 4 / 3
0 / 12 / 8 / 6
1 / 17 / 12 / 10
2 / 22 / 16 / 15

VIDEO #4: Mrs. Workman. Find the slope of a line that passes through each pair of points.

Skip video #5.

VIDEO #6. Mr. Rutherford. Find the value of r so that the line through (-6, -3) and (-1, r) has a slope of 2.

You are responsible for accessing the online textbook at home tonight to compare your notes to the videos shown in class.

They are accessible from Chapter 3 Section 3.

Homework: page 177 #’s: 1, 2, 5, 6, 8, 10, 11, 12