Topic 3: Use Functions to Model Relationships - Revision

• Function A

• Function B

• Function B

• Function A

Graph the ordered pairs from the table. Determine if the relation is a function. Table: ordered pairs (−3, −4), (0, 5), (1, −5), (3, 1).

• The relation is a function.

• The relation is not a function.

Graph the ordered pairs from the table. Determine if the relation is a function. Table: ordered pairs (−1, 3), (1, −1), (2, 2), (1, 3).

• The relation is a function.

• The relation is not a function.

Determine which graph represents a function.

• Graph a: a sideways curved graph (opening to the right) that fails the vertical line test.

• Graph b: an oval (ellipse) centered near the origin that fails the vertical line test.

• Graph c: several separate plotted points with no repeated x-values that pass the vertical line test.

• Graph d: an upward-opening parabola that passes the vertical line test.

The graph shows the height of a hiker above sea level. The hiker walks at a constant speed for the entire trip. Describe the behavior of the function in each interval (1) through (5).

• The function is increasing in intervals 1, 3, and 4. The function is decreasing in interval 5. The function is constant in interval 2.

• The function is increasing in intervals 1 and 3. The function is decreasing in interval 5. The function is constant in intervals 2 and 4.

• The function is increasing in intervals 1 and 3. The function is decreasing in intervals 4 and 5. The function is constant in interval 2.

• The function is increasing in intervals 1, 2 and 3. The function is decreasing in interval 5. The function is constant in interval 4.

Select a graph for the situation. You wait for the express bus for 30 minutes, get on and ride the bus non-stop for 3 miles, and then walk another mile to your home. Choose the graph of distance (mi) versus time (min) that shows distance staying at 0 for 30 minutes, then a steep increase to 3 miles, followed by a slower increase to 4 miles.

• a

• b

• c

• d

A hiker climbs up a steep bank and then rests for a minute. He then walks up a small hill and finally across a flat plateau. Which sketch of elevation versus time matches this description?

• a

• b

• c

• d

• a

• b

• c

• d

• yes

• no