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Reflections and Thinking
Posted on September 29th, 2012
If anyone associated with my HS job reads this, I’m only talking about a few of you kids. Most of you are doing the right thing! Keep it up! It is what makes that job fun and why I come into work every day to be with you. If you are my Principal or the AP, I’m coming to talk to you Monday about my concerns.
In a couple of my HS classes, I’m a bit discouraged because there seems to be a lot of outside school behavior that is getting in the way of several students learning. (I’m not going into depth because I still want that job ) This behavior seems more wide spread than it has been in the past. Maybe it is just the mix of students I have this year? It is depressing because they are bright people making poor decisions.
How is this related to what follows? Well in the midst of despair there is always a glimmer of joy:
In my online cc Precalculus course, I have student’s respond to some discussion type questions from the text. This morning I found the following, which I thought I’d share:
A student responded and asked:
Polynomial functions all have the same domain- all real numbers, or (-infinity, infinity). This is what makes them continuous. They reach across all values of x on a graph without breaks or interruptions.
What makes them have soft edges, at turning points, instead of sharp or corners?- is this the exponential effect? What functions have sharp corners, only those with absolute value in them?
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Wow that made me take a step back and ask myself how should I answer this without getting into how a function might not be differentiable?
Here was my response:
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A great question Stu Dent. You’ve really made me consider how to answer it.
In calculus you’ll learn that as a function changes from an increasing function to a decreasing, the slope of the function changes from a positive value to a negative value, momentarily having 0 slope at the maximum point.
This is reversed when the function changes for a decreasing function to an increasing function.
For functions like
f(x)=|x|
there is not a gradual change in the slope. It takes a sharp corner.
This is really a specific case example, but I hope it answers your question without confusing everyone.
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How did I do answering without getting too in depth?
It is nice to work with people who are thinking and not distracting themselves. Isn’t this why we do this job?