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Wednesday, December 3, 2014

Blog Post 4

Concavity

This lesson will teach students what concavity is and what it looks like on a graph. Also, I will go over how the graph of a line can be increasing and decreasing at the same time that it is concave up or down.

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 The graph of a linear function is a straight line because the average rate of change is constant. But, not all graphs of functions are straight lines, they can be bent upwards or downwards. This upwards and downwards is called concavity.

  • ·      A graph that is bent upward is concave up.
  • ·      A graph that is bent downwards is concave down.



The graph of a line can also be increasing or decreasing at the same time that it is concave up or down.

  • ·      A graph is increasing when the line is rising from left to right.
  • ·      A graph is decreasing when then line is falling from left to right.


Note: If a function has a constant rate of change, its graph is a straight line and it is neither concave up nor concave down. BUT, it can still be increasing or decreasing depending if it is rising or falling from left to right. 


EXAMPLES OF CONCAVITY UP/DOWN AND INCREASIND/DECREASING


Concave Up / Increasing
Concave Up / Decreasing














Concave Down / Decreasing
Concave Down / Increasing
















Photos taken from:

http://www.biology.arizona.edu/biomath/tutorials/functions/Properties.html



6 comments:

  1. The graphs you chose are a great illustration of concavity. You explained when a graph is either concave up or concave down and you also discussed when it is increasing or decreasing. Good point about the rate of change affecting the graph.

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  2. The graphs you provided are really helpful in explaining concavity

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  3. The graphs perfectly describe increasing, decreasing, concave up and concave down! good job!

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  4. milana,

    really great lesson! your images really helped support your explanation of concavity. i really like how you compared lines with curves to differentiate what concavity looks like. a real world example using this concept would have been a great addition, but still great job!

    professor little

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