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Topic: stop teaching shifting & stretching?
Replies: 14   Last Post: Oct 19, 1998 8:58 AM

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 LnMcmullin@aol.com Posts: 10,730 Registered: 12/3/04
Re: stop teaching shifting & stretching?
Posted: Oct 12, 1998 8:34 PM

In a message dated 10/12/98 14:22:50 Eastern Daylight Time,
Bill_Larson@compuserve.com writes:

<< Since my calculus students will have graphers, is it the =

consensus that I should stop teaching my precalculus =

students such tricks to aide graphing as shifting & stretching =

functions and symmetry? I'd love to stop teaching this, because it =

would free time for other "essential" topics, which I do not =

get to.
>>

I suggest you continue to teach it. It is a very important idea. I can't
imagine a good pre-calculus course without these topics. It should be covered
somewhere (trig functions make good examples).

Also consider the 1998 AP Exam question AB2/BC2: quite a few students answered
and justified part (d) be using the fact that bxe^(bx) is a stretching (or
shrinking) of the function 2xe^(2x) analyzed earlier in the same problem and
therefore the absolute minimum does not change. (They received full credit of
course -- as well they should)

Lin McMullin
Ballston Spa, NY

Date Subject Author
10/12/98 William J. Larson
10/12/98 Chris & Sheila King
10/12/98 Wayne Bishop
10/12/98 LnMcmullin@aol.com
10/12/98 dslomer
10/12/98 Jerry Uhl
10/13/98 Lou Talman
10/13/98 Lou Talman
10/14/98 Victor Levine
10/14/98 William J. Larson
10/14/98 dslomer
10/14/98 CalcPage@aol.com
10/15/98 William J. Larson
10/19/98 BDS McConnell
10/19/98 Albert Goetz