TI-86 and radical expressions
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TI-86 and radical expressions
Stoops Ryan D <stoopsr@MSOE.EDU> writes:
> I know this has been brought up before, but I didn't hear the answer and
> I was wondering if there is any way to convert a decimal to a radical eg.
> .86~~ would be equal to square root 3 /2. thanks
The problem is 0.86WHAT?? A calculator that uses floating-point
storage (like all the TI-8x's) can only store a truncated representation
of a number. If you ask what is a radical expression corresponding to
0.8660.... (that's the first four digits of the decimal expansion of
sqrt(3)/2 you just might get back the answer 109*sqrt(2)/178 :-)}
The TI-92, in contrast, has the power to store (and work with) exact
expressions involving powers and radicals. The difficulty there is
knowing whether for a given application one really has sqrt(3)/2, say,
exactly or just some result that is close to this value (say if you are
calculating the sine of an angle that measures _about_ 60 degrees).
There has been some discussion on the MATHEDCC list of why using
calculators can help a math instructor get at important questions
relating to the nature of numbers and their representations (if the
instructor is interested in this topic -- and one would hope for the
sake of students that he or she would be).
RWW Taylor
National Technical Institute for the Deaf
Rochester Institute of Technology
Rochester NY 14623
>>>> The plural of mongoose begins with p. <<<<