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Integral with unexpected result
05-30-2016, 04:42 AM
Post: #1
Integral with unexpected result
In home, int ((e^x)/(ln x)) from .01 to 1 produces ~58.9

In CAS, [~-23.55 ~-86.48]

The integral should be infinite.

This on hand held version 10077
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05-30-2016, 04:43 AM
Post: #2
RE: Integral with unexpected result
Correction...In home, the result is ~-58.92
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05-30-2016, 04:58 AM
Post: #3
RE: Integral with unexpected result
It's impossible to get infinity by a numerical method (it would require finding an equivalent at x=1). The CAS displays a big warning in the terminal before returning two values that are not close at all, a clear sign that the values are garbage.
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05-31-2016, 04:44 AM
Post: #4
RE: Integral with unexpected result
Hello,

In home, the numerical method does seem to converge to a solution

One of the "good" thing about the method used in home is that it never evaluates the function on the 'edges', so it can deal with a function that is not defined there...
but, for fast moving functions, this can lead to weird results.

Cyrille

Although I work for the HP calculator group, the views and opinions I post here are my own. I do not speak for HP.
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