Crash when Solve for Integral with 15C

[rprosperi]

(09-02-2017 08:55 PM)Gerson W. Barbosa Wrote:  

(09-02-2017 08:34 PM)Dieter Wrote:  The integration limits have to be substituted, i.e. they are now 0³ = 0  and  6³ = 216.

Yes, because of the variable change suggested by you, BTW, as an attempt to improve the execution time.

I did

u=x^3 -> x=u^(2/3)

du/dx=3*x^2 -> dx=du/(3*x^2)

-> Integ(e^x^3 dx, 0, 6) = Integ(e^u/e^(2/3), 0, 216)

Interestingly the speed improvement on the 34C, as reported by AndyGer, and the HP-41CV is about only 20%, not so good as the 50% I had observed on the HP-15C emulator.

Gerson.

PS: W|A gives a closed form solution for the latter in terms of Gamma and Incomplete Gamma functions:

1/6(1+i*sqrt(3))*(Gamma(1/3)-Gamma(1/3,-6^3))

Unfortunately the a Incomplete Gamma implementation on the WP34S won't handle these arguments.

Thanks for breaking that down for us mere mortals Gerson. I had puzzled over it for a few moments and had just given up.