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Re-integration problem of abstract function - yangyongkang - 04-11-2019 12:44 PM
Recently I tried to solve the re-integration of some abstract functions with xcas and found some problems.for example:
Code:
diff(integrate(integrate(f(sqrt(x^2+y^2)),y,-(sqrt(t^2-x^2)),sqrt(t^2-x^2)),x,-t,t),t)Code:
2pi*diff(f(t),t)*tCode:
"Integral in limit not implemented yet Error: Bad Argument Value"Related issues
Code:
∫(∫(e^(-(x^2+y^2)/2),y,-(sqrt(a^2-x^2)),sqrt(a^2-x^2)),x,-a,a)Code:
integrate(sqrt(pi)*1/(sqrt(2))*erf(sqrt(a^2-x^2)*exp(ln(2)/2)/2)*exp(-x^2/2)-sqrt(pi)*1/(sqrt(2))*erf(-sqrt(a^2-x^2)*exp(ln(2)/2)/2)*exp(-x^2/2),x,-a,a)In fact, we can get the correct answer through polar transformation.
Code:
∫(∫(e^(-r^2/2)*r,r,0,a),x,0,2π)Code:
2*pi*(-exp(-a^2/2)+1)Looking forward to the update of hp prime firmware in 2019
RE: Re-integration problem of abstract function - yangyongkang - 04-25-2019 12:20 PM
Let's take a look at this issue.
RE: Re-integration problem of abstract function - Eddie W. Shore - 04-30-2019 07:30 PM
My only suggestion is to try integration and differentiation one step at a time (inside out). Patience may be needed.
I don't know if turning complex mode off in CAS would help.
Eddie.
RE: Re-integration problem of abstract function - Hans S. - 04-30-2019 08:25 PM
(04-11-2019 12:44 PM)yangyongkang Wrote: Recently I tried to solve the re-integration of some abstract functions with xcas and found some problems.for example:brings to mind chinese figure skaters (f.) or the so-called pianist lang lang: indefinite exercise, no (artistic) result.
diff(integrate
H.