I don't know about ability to sketch certain algebraic equations, but I have seen that the words "constant," "linear," and "quadratic" are disconnected from the graph shapes if the students have to draw them. They can recognize them if I draw them, which really puzzles me.
Students have difficulty in actually producing plots of data, especially when they have to choose the axis scales. We force them to do hand plots for labs the first half of the semesters (plotting d vs t^2, d vs t, <v> vs t, range vs theta, etc.) just in case they don't have a computer around when they need to plot something, and to make them think about ratios, scaling, perspective, linearity, etc. I still fear that the "skill" disappears when we let them use the computer for their graphing. When I let them use the computer, I force them to describe the type of curve....[primal screams heard].
Sigh...
Bill N
-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Dr. Richard Tarara
Sent: Monday, March 22, 2010 12:20 PM
To: Forum for Physics Educators
Subject: [Phys-l] Graphing algebraic equations
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
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Richard W. Tarara
Professor of Physics
Saint Mary's College
Notre Dame, IN
rtarara@saintmarys.edu
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Free Physics Software
New multi-input energy simulator--plays similar to the Montana State analog
computer.
www.saintmarys.edu/~rtarara/software.html
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