You can make integrals faster reducing precision of HP48
For example, lets integrate:
It says 0.035033971515, after 43 seconds.
Settinng format to 2 FIX we get Result: 0.03, after 4 seconds.
Put now the format to STD to have full digits. Result: 0.0346435195954.
The precision difference between both calculus is
0.039041%, in this case.