Re: [Phys-l] Graphing algebraic equations

["Anthony Lapinski" <Anthony_Lapinski@pds.org>]

I agree, Calculators are nice, but they don't really teach students how to
think. I'm in a private high school setting. We begin the year with linear
motion, including basic d-t, v-t, and a-t graphs. Major problem for
students, even the "honors" ones. I use some graphing questions for
multiple choice. Some of the weaker students think "increasing" means
"positive" and "decreasing" means "negative." And many students can't
convert simple fractions to decimals. Emphasis on calculators might
partially be to blame. It is what it is, but what are we as a society to
do?

Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu> writes:
> This problem starts in the high school where the math teacher requires a
> graphing calculator but invariably fails to instruct them how to
> interpret the graphs they get.  Students never have to actually draw a
> graph until they get to my physics class where they have to draw the
> resulting data on graph paper for some newtonian mechanics lab, such as
> displacement v time or velocity v time and they can't figure out which
> variable goes on the x axis and which goes on the y axis.  They
> eventually can place the *dots* on the graph, but then can't figure out
> how to draw the curve.  (They want to connect all the dots even though
> actual data often doesn't follow a pure curved pattern.  Then I bring out
> "Mimi and Fifi", my French curves, and teach them how to show a smooth
> best fit curve.  They have never seen a French Curve set before and
> probably never will, because when they go to the math class again they
> are right back to the calculators.   They also cannot interpret or
> interpolate
>
>  from the given curve and often can't place the proper interval of data
> on the axes.  (In the beginning they all want to put the actual data
> numbers which gives a nice straight line)  In the end, they think I am a
> throwback and that they will probably never have to do what I have
> instructed about graphing.   So, they get to you and have become addicted
> to the easy way out... using the caucluator and the heck with what it all
> means!.
>
> Marty
>
> ps:  BTW, I tell them that in high school physics I  the only calculator
> they really need is a $12 TI-30.  Most of them can't use 99% of the
> functions on the TI-85's anyway!  
>
>
> On Mar 22, 2010, at 1:19 PM, Dr. Richard Tarara wrote:
>
> > Are other people seeing problems with this--students ability to sketch 
> > graphs of algebraic expressions?  This year is the worst I've seen. 
> The 
> > context is primarily in doing Gauss' Law for spheres and cylinders and 
> > wanting a field versus distance graph.  I'm getting a lot of nonesense
> even 
> > after we've done numerous examples (and pure gibberish the first time
> this 
> > is asked).  [We're talking about Chemistry and Engineering students
> with 
> > pretty solid calculus backgrounds.]   I'm wondering if this might not
> be 
> > partly due to graphing calculators--they've graphed many functions but
> never 
> > internalized what shapes go with what functions.   Again--is this an 
> > isolated observance or are others seeing this too?
> >
> > Rick
> >
> > ***************************
> > Richard W. Tarara
> > Professor of Physics
> > Saint Mary's College
> > Notre Dame, IN
> > rtarara@saintmarys.edu
> > ******************************
> > Free Physics Software
> > New multi-input energy simulator--plays similar to the Montana State
> analog 
> > computer.
> > www.saintmarys.edu/~rtarara/software.html
> > ******************************* 
> >
> > _______________________________________________
> > Forum for Physics Educators
> > Phys-l@carnot.physics.buffalo.edu
> > https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
>
> _______________________________________________
> Forum for Physics Educators
> Phys-l@carnot.physics.buffalo.edu
> https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l