int(1/x^2,x,-1,1)


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int(1/x^2,x,-1,1)



A few more thoughts on this thread:
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Synopsis:

The '85 responds to fnInt(1/x^2,x,-1,1) (after a yawning gap of time)
with "ERROR 02 DIV BY ZERO."

Derive XM for DOS gives INT(1/x^2,x,-1,1) = -2

and from Michael Keyton's report, the TI-92 has
INT(1/x^2,x,-1,1) = infinity.

It seems the '92's answer is the best guess of all!
_______________________________________________________
So here's another test:
The '85 responses to both fnInt(1/x,x,0,1) and fnInt(1/x,x,-1,1) are
"ERROR 33 TOL NOT MET" (unless tol is cranked to about 1.9) and
"ERROR 02 DIV BY ZERO," respectively.

Derive XM responds to INT(1/x,x,0,1) with infinity,
while INT(1/x,x,-1,1) gives -i*pi, which looks like an
application of Cauchy's residue theorem?!

What does the '92 do?
________________________________________________________

Geoff Hagopian,
Palm Desert, CA



Digest:
.... I don't have the '92, but I'm a Deriver from way back.  One of
.... the curious bugs in Derive is that, if you integrate 1/x^2 from
.... -1 to 1, it give you -2.
... <The '92> gives infinity.
... What version of Derive are you using?
.. I have Derive XM 3.05
. David Stoutmeyer really works hard to purge incorrect solutions
. in Derive. <snip...>


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