## Wednesday, February 6, 2008

### Wanted Mathematical Words

CBC Radio ran a highly entertaining radio spot called Wanted Words, in which listeners submitted suggestioned new words to describe things:
• What do you call the long, cold, dark Canadian period between New Year's and Good Friday? Forevuary.
• What do you call someone whose plants always die prematurely? Hortikillturist.
• What do you call @? Atpersand, ampersend, Circle-A (from a rancher in B.C.)
• What do you call the warmth left behind when you sit in a recently occupied seat? Bumcano.
In working on CLIPS, we have come up with a few surprising wanted Mathematical words:
• What do you call the superclass of transformations that take (x,y) and map it to (x,ay)? For some values of a we call it a stretch, for others a compression, for still others the composition of a reflection and a stretch/compression. Some sites seem to allow for a vertical stretch of factor 1/2, but would you allow one of factor -3?
• What do you call the line in the middle of a sinusoidal? Medial axis, median line, mid-range, mean level (like mean sea level)...
Don't you think it is wild that there doesn't seem to be a least one word around for these things? I would be happy to hear any suggestions that you might have - maybe CLIPS will use your suggestion. How about the Isenegger-Clarke line? A compstretchion?

MrsP said...

Ross, we should get Junior/Int students to come up with some combinations? I'm not sure how nice or appropriate they might be.

Ross Isenegger said...

Let me know if they come up with any. I finally found one site that called the median line the "baseline", and the first intersection with it the "base point" which is placed by knowing the phase shift.

Mike said...

The mapping you consider is a linear transformation of the 2nd coordinate; or, if you like, the mapping is a "multiplicative effect in the 2nd coordinate". I've certainly run into this in the classroom, and resolved it by using the word "multiplicative effect" instead of stretch/compress.

The line you seek is a horizontal line of symmetry in the sinusoidal curve; or, if you like, "the midline of the graph".

Great Blog!