HP Forum Archive 21

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Prime: fsolve with [..] Message #1 Posted by Helge Gabert on 6 Oct 2013, 10:38 p.m. I was pleasantly surprised that root finding for certain functions with fsolve and [interval] finds more than one solution with one call, e.g., fsolve(x^(3-4)-3,x,0..6) finds both roots, [1.57.. and 3]. This is in CAS view only. In Home view, any attempt to enter the interval (and changing x for X) gives an error message: two decimal separators in input! One quirk: if the function is stored in, say, F7, in CAS view, executing fsolve(F7,'X',0..6) returns only one root (3), IF the Function app is the current app. If I switch to SOLVE as the current app, both roots are returned. ??? What object type is the interval [..]? Can that be tested for in a program?

Re: Prime: fsolve with [..] Message #2 Posted by Helge Gabert on 6 Oct 2013, 11:00 p.m., in response to message #1 by Helge Gabert Sorry, typo . . the function should read X^(4-X)-3 in F7 (or x^(4-x)-3 in CAS view).

Re: Prime: fsolve with [..] Message #3 Posted by parisse on 7 Oct 2013, 6:35 a.m., in response to message #1 by Helge Gabert Quote: What object type is the interval [..]? Can that be tested for in a program? It's a symbolic, if ii:=a..b then ii[0]=='..'

Re: Prime: fsolve with [..] Message #4 Posted by Helge Gabert on 7 Oct 2013, 10:41 a.m., in response to message #3 by parisse Thank you! I hope that in a later revision, symbolic expressions can be passed as arguments to programs!

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