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Topic:
Re: Math B #30
Replies:
21
Last Post:
Jul 24, 2007 11:34 AM




Re: Math B #30
Posted:
Jun 18, 2007 7:05 PM


I agree that students should be able to tell the min without a calculator. But in this case we felt that the first question was ambiguous: does it mean the minimum for all times, or the minimum from 1970 to 2000? If it's the latter, then 29.464 is correct (in degree mode). (As the question was intended, in radian mode, there is no ambiguity in the question because under either interpretation the min is 10.)
 Evan Romer Susquehanna Valley HS
On Sunday, June 17, 2007, at 07:31 AM, fsasqr@netzero.com wrote:
> The only problem with this is that the student should be able to tell > me the minimum without use of the calculator. I teach them about the > amplitude and the vertical shift and that they can tell the max and min > by adding the vertical shift to the max and min determined from the > amplitude. Then there is no other answer besides 10 for the min and if > you are in degrees you can say it does not occur, but to say the min is > 29.464 means an over reliance on the calculator and to me is not worth > 3 out of 4 points. Lucky for me I did not grade that question. > >   Evan Romer <eromer@echoes.net> wrote: > Actually, that's a reasonable answer for the student who had his or her > calculator in degree mode and who read the question carefully. In > degrees, the snowfall function decreases slowly from 30 inches in 1970 > to 29.464 inches in 2000. Some of our "degrees" students students said > the minimum snowfall was 29.464 inches and that it occurred in 2000. > Others who read the question more carefully noticed that the first > question did not specify a time frame: what is the minimum snowfall for > this region [for all years]? 10 inches. In which years 1970 to 2000 did > the minimum fall? It did not occur during that time period (it occurs > at t=286.48 years, i.e. the year 2256). > > For both of these students, we took off for the degrees vs. radians > error, but gave full credit for the rest, *IF* they showed appropriate > work and made clear what they were doing. After all, they did the > problem correctly answer once they were in degree mode (given that the > first question is ambiguous if you're in degree mode). A bald answer of > 29.464 and 2000, or a bald answer of 10 and never, did not receive any > credit. > >   Evan Romer > Susquehanna Valley HS > > > On Friday, June 15, 2007, at 02:31 PM, Tony Geraci wrote: > >> >> Also we were wondering in 31 how you could have a minnimum snowfall in >> part a, but in part b say that it never happens? >> >



