Understanding Graphs: Positivity, Negativity, and Trends

The video tutorial explains how to determine when a function is positive, negative, increasing, or decreasing by analyzing its graph. It uses the Y-axis and zero line to identify positive and negative values, and employs a roller coaster analogy to describe increasing and decreasing functions. The tutorial provides clear instructions on how to write these conditions mathematically.

What is the criterion for a function to be considered positive?

• When the graph is below the zero line on the Y-axis

• When the graph is above the zero line on the Y-axis

• When the graph is at the zero line on the Y-axis

• When the graph is parallel to the X-axis

In which interval is the function positive according to the video?

• Between points A and B, and starting at C

• Between points B and C

• Less than point A

• Greater than point D

Why is point C not included in the positive interval?

• Because it is positive

• Because it is zero

• Because it is undefined

• Because it is negative

How is a negative function interval identified?

• When the graph is at the zero line on the Y-axis

• When the graph is parallel to the X-axis

• When the graph is below the zero line on the Y-axis

• When the graph is above the zero line on the Y-axis

Which intervals are identified as negative in the video?

• Between points A and B

• Less than point A and between points B and C

• Between points D and E

• Greater than point C

What does it mean for a function to be increasing?

• The graph is moving downwards

• The graph is at zero

• The graph is moving upwards

• The graph is constant

In which intervals is the function increasing according to the video?

• Between points B and C

• Less than point D and greater than point E

• Less than point A

• Between points A and B

What does it mean for a function to be decreasing?

• The graph is moving upwards

• The graph is constant

• The graph is at zero

• The graph is moving downwards

Which interval is identified as decreasing in the video?

• Between points A and B

• Between points D and E

• Less than point C

• Greater than point E

What analogy is used to explain increasing and decreasing functions?

• A boat sailing

• A plane taking off

• A roller coaster

• A car on a highway