Re: [MATHEDCC] Computer Algebra Systems

Phil Mahler (mahlerp@admin.middlesex.cc.ma.us)
Sat, 07 Mar 1998 12:54:00 EST5EDT4,M4.1.0,M10.5.0

>>> x^6 - 2x^5 + x^4 + 3x^3 - 4x^2 + x - 5
>>> with limits of 0 and 1. About any polynomial of degree 6 or greater will
>>>be slow.
>
>I used tht TI-82, It took about 3 or 4 seconds to find a numerical answer.
>I also used a Program used from the Harvard Brief Calculas materials using
>numerical approximation of 100 divisions and got "close enough." So I am
>interested in why the Powerfull TI-92 struggles?
>
>What is the Derive system doing differently?
>
>Vern Kays

I don't know myself, but here's some more data.

The lower bound of zero
really seems to make a difference. On [0.1,1] the result is immediate.

There is an nInt (numeric integration) function on the 92 which works
fine on [0,1].

Only the call to the symbolic integration funciton seems problematic.
According to the TI manual, if there is an antiderivative, That is found
and used. And the exactness of the answers on anything but a lower bound
of zero seems to confirm that. But obviously zero gums up the works.

Phil Mahler
Middlesex CC
Bedford, MA
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