Error in integration (10637)

[slawek39]

   

Emulator behaves differently.

[Alberto Candel]

My Prime (also 10637) returns 2 values, one exact and one approximate, and a warning that says that the Prime cannot verify that they are the same.

The exact is (1/3) [Gamma(1/3,-216)-Gamma(1/3)]
and the approximate is 5.96393809188E91,

There is no documentation entry for the Gamma(x,y) function that I can find.

[Marcel]

Hi,
In Home view, Slavek is right...
Marcel

[Alberto Candel]

Well, if, in HOME, I type what it shows in slawek image, my prime returns Syntax error. It seems that I need to prepend CAS to the integral. That is why I thought slawek was in CAS.

[Marcel]

Hi,
I have input the same integral and I have the same bizarre output!
Marcel

[Alberto Candel]

I want to add, Gamma(1/3,-216) is the incomplete Gamma, but the Prime doesn't seem to know waht to do with it other that display it. On approx(Gamma(1/3,-216)) it returns "undef".

[parisse]

You get two results from CAS: the exact one and the result of a numeric evaluation. Unfortunately, the exact one can not be evaled numerically because the argument of the incomplete gamma function is too large, therefore the CAS can not compare the two values that's why you get the warning.

[Jan_D]

With version 8151 I have in HOME view the same approximate value as in CAS, and no exact value in CAS.

In HOME view I entered uppercase X, in CAS lowercase x.

[Alberto Candel]

I noticed that XCAS formats the answer to this integral in a slightly different way. Maybe the Prime could do that also? And for future upgrades, could it be possible to document that Incomplete Gamma? (Thanks)