Improper Integrals with the HP-15C LE & CE

[Namir]

Ok, I decided to retest using specific FIX modes and comparing. The LE and CE did produce the same results as expected. The CE seemed a bit slower in giving the results. When the FIX mode was between 2 and 3, thre results appeared quickly. FIX 4 took a few seconds more. The time for the integration seemed to me to rise exponentially.

The delya in obtaining a result also depends on the integrated function. Some functions are easier to integrate thhan others (within the context of improper integrals).

intgeral of 1/sqrt(x) for x = 0 to 1 (exact is 2)
HP-15 LE gave:
1.99 using FIX 2
1.999 using FIX 3
1.9999 using FIX 4
Using FIX 5 calculator kept flashing "running" for quiite a while!

HP-15C CE gave:
1.99 using FIX 2
1.999 using FIX 3
1.9999 using FIX 4 (took a while)
Using FIX 5 calculator kept flashing "running" for quiite a while!


intgeral of cos(x)*log(x) for x = 0 to 1 (correct is -0.9460830703670)
HP-15C LE gave:
-0.94 using FIX 2
-0.946 using FIX 3
-0.9460 using FIX 4
-0.94608 using FIX 5
-0.946083 using FIX 6
-0.9460830 using FIX 7
-0.94608307 using FIX 8

HP-15C CE gave:
-0.94 using FIX 2
-0.946 using FIX 3
-0.9460 using FIX 4
-0.94608 using FIX 5
-0.946083 using FIX 6
-0.9460830 using FIX 7
-0.94608307 using FIX 8



intgeral of 1/√(-Ln(x)) (correct is 1.77245385091)
HP-15C LE gave:
1.76 using FIX 2
1.771 using FIX 3
1.7723 usin FIX 4
Using FIX 5 calculator kept flashing "running" for quiite a while!

HP-15C CE gave:
1.76 using FIX 2
1.771 using FIX 3
1.7723 usin FIX 4
Using FIX 5 calculator kept flashing "running" for quiite a while!