HP42s first major program (Double Integral) Best way to approach?

[J-F Garnier]

(05-27-2020 01:25 AM)DM48 Wrote:  Any help getting me pointed in the correct direction would be appreciated. I am assuming I need to to solve the inner integral and then the outer integral on the 42s separately.

One possible approach is to use the built-in integrate function for the inner integral, and code the Romberg algorithm in RPN for the outer integral. Speed penality should not be too large, since most of the time is spent in the inner integral.
The Romberg algorithm is well known, quite easy to implement and using low resources (the HP-42S has ample memory for it). The algorithm has been discussed recently here.

J-F