Numerical integration - Printable Version

Numerical integration - Printable Version

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Numerical integration - scublue - 02-01-2018 02:37 AM

HP prime can not give the right answer such as int(sin(1/x)/x^(3/2),x,1,+infinity), how cold i calculate such kind of numerical integration. Thank you very much.

RE: Numerical integration - Joe Horn - 02-01-2018 04:03 AM

In CAS, use a lowercase "x" for the variable, and use "1." (instead of "1") for the lower limit, and you'll get 0.620536603447 which is the correctly rounded answer. Including a decimal point forces a numeric result instead of a symbolic result.

Or you can use "1" as the lower limit, press Enter, and then press the [a b/c] key to approximate it.

Or change the "Exact" mode in CAS Settings to OFF.

RE: Numerical integration - Carlos295pz - 02-01-2018 04:08 AM

Xcas also does not find an answer, they must have an extraterrestrial mathematical reason xD

RE: Numerical integration - scublue - 02-01-2018 07:00 AM

However, i got the answer like this 0.6417....

RE: Numerical integration - salvomic - 02-01-2018 07:48 AM

(02-01-2018 04:08 AM)Carlos295pz Wrote: Xcas also does not find an answer, they must have an extraterrestrial mathematical reason xD

in CAS there is an extraterrestrial mathematical reason also for simply ∫SIN(1/x) or ∫COS(1/x) :-)

RE: Numerical integration - Tim Wessman - 02-02-2018 05:23 PM

As Joe said, do it in the CAS screen and you get the desired result. The problem with doing it in the home is you hit numerical limitations with 12 digits and also approximations.

RE: Numerical integration - Joe Horn - 02-04-2018 05:02 AM

(02-01-2018 07:00 AM)scublue Wrote: However, i got the answer like this 0.6417....

You have to be more careful with where you put parentheses. Your original posting's expression is different from your recently posted expression. You can see them both here:

[Image: integral.png]