an easy integral. not for maple 6. (31.10.00)

Don Hartig

The following calculation was made in Maple 5.1 (courtesy of George Luna):

> restart: 
> Int(Int(sqrt(x^3+1),x=sqrt(y)..1),y=0..1); 
 
                     1    1 
                    /    / 
                   |    |              3 
                   |    |        sqrt(x  + 1) dx dy 
                   |    | 
                  /    / 
                    0    sqrt(y) 
 
> evalf(%); 
 
                             .4063171388 
Try it in Maple 6.

It is corrected with Maple 7. (U. Klein)

HARALD PLEYM (2.11.00)

Here is what I get:

>A:=Int(Int(sqrt(x^3+1),x=sqrt(y)..1),y=0..1); 
> evalf(A); 
Error, (in depends) too many levels of recursion

But if you try

A:=Int(Int(sqrt(x^3+1),x=sqrt(y)..1),y=0..1); 
in R5 you get some of the same error 
 
evalf(%); 
Error, (in LinearProp) too many levels of recursion

TANGUY Christian (6.11.00)

Funny indeed, all the more so when you try int(int(...)) instead of Int(Int(...)). The first integration is performed, but an evalf(%) then freezes Maple 6 on my Pentium II. 2/9*(sqrt(8)-1) might be reached after SOME time..