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Topic: Re: Calculator question
Replies: 0

 Dave Slomer Posts: 46 Registered: 12/6/04
Re: Calculator question
Posted: Jul 23, 1998 11:40 AM

>Jerry Brodkey wrote:
>

>> One of my former students who is now starting to teach asked me the
>> following question for which I don't have a good answer;
>>
>> On the TI-82: 10/5*2 equals 4
>>
>> but 10/5(2) equals 1.

This is the (in)famous "implied multiplication" which takes precedence over
division.

>> The order of operations rules that I've been using for twenty years
would
>> agree with the answer equal to one. Multiplication and division are
>> "equal" in power and you work from left to right. The parentheses in

this
>> case don't change the order of operations.

OK. Not (in)famous--INfamous. TI just shouldn'ta done it. They did it to
make sin 2x mean sin(2x)--noble goal, but caused problems, such as the one
here. Graph the line "y equals one-half of x" via y1=1/2x. Ya get a
hyperbola.

This feature (it is NOT a bug--it was carefully planned) is not present on
the 83 and up but IS on the 85 (which predates even the 82).

Dave Slomer
Retired AP Calculus teacher
Will Algorise For Food
http://www.geocities.com/capecanaveral/lab/8692