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Topic: error in an integral, Rubi 4.3, QuotientOfLinearsParts error
Replies: 10   Last Post: Dec 9, 2013 5:44 PM

 Messages: [ Previous | Next ]
 Nasser Abbasi Posts: 6,677 Registered: 2/7/05
error in an integral, Rubi 4.3, QuotientOfLinearsParts error
Posted: Nov 29, 2013 8:34 PM

Fyi,

Rubi 4.3, Mathematica 9.02, windows 7

-------------------------
ClearAll[t]
Assuming[t>0,
Int[Sqrt[1+40 t] Sqrt[1+(162 t^2)/(4-2 I Sqrt[77])] Sqrt[1+(162 t^2)/(4+2 I Sqrt[77])],t]
]
------------------------

gives

\$RecursionLimit::reclim: Recursion depth of 1024 exceeded. >>
General::stop: Further output of \$IterationLimit::itlim will be suppressed during this calculation. >>
QuotientOfLinearsParts error!
Power::infy: Infinite expression 1/0 encountered. >>
Infinity::indet: Indeterminate expression ComplexInfinity+ComplexInfinity encountered. >>

But, using Mathematica own Integrate on same integral, does not give these
errors (but remains unevlauated)

--------------------------------
Assuming[t > 0,
Integrate[
Sqrt[1 + 40 t] Sqrt[1 + (162 t^2)/(4 - 2 I Sqrt[77])] Sqrt[
1 + (162 t^2)/(4 + 2 I Sqrt[77])], t]]
----------------------------------

Also, doing

ShowSteps = True;

did not show any steps for some reason for this integral before the
error showed up. So hard to know which step caused it.

--Nasser

Date Subject Author
11/29/13 Nasser Abbasi
11/30/13 Nasser Abbasi
11/30/13 Nasser Abbasi
11/30/13 Axel Vogt
11/30/13 Nasser Abbasi
11/30/13 Herman Rubin
11/30/13 Nasser Abbasi
12/2/13 Axel Vogt
12/6/13 Albert D. Rich
12/9/13 Axel Vogt
12/9/13 Albert D. Rich