Using the TI-36X Pro solver to find the unknown upper bound of a definite integral

Something very impressive that the TI-36X Pro and the CASIO fx-991EX are able to do: find the unknown upper bound of a definite integral required to provide a desired result (i.e. area under the curve).
What is not impressive (well, I guess it actually is impressive, but not in a good way) is how long it takes the TI-36X Pro to do this -- 3 minutes and 41 seconds! But, it did figure it out!

[@irishchocolate3872]

The Casio ClasszWiz took approximately a minute to solve it. Its processor is a little faster than the 36XPRO but it is amazing these 2 inexpensive calculators can do this. As far as the Prime I heard that one F16 pilot said his cockpit wasn’t as complicated as the HP’s most capable calculator. Great machine but a little too complicated for its own good.

[@scottcollins7513]

Thanks again for inspiring the video, I.C. Yes, Prime is amazingly powerful, but overkill for what I typically need and not as easy to use as I would prefer.

[@Th-et8xf]

Ti 30 x pro ( new version of 36x pro) Mathprint took a little less than 14 seconds without the guess

[@theedspage]

I can verify that this problem can be solved on the Casio fx-CG50 and fx-9750GIII/9860GIII through the Equation-Solver application in a relatively short amount of time.

[@scottcollins7513]

Good to know, Edward. Thanks for the info.

[@irishchocolate3872]

I also tried this on the TI-nspire cx cas and I think it almost broke the machine. It kept on going with a clock on the screen continuously moving. I couldn’t shut it off or break the solve sequence. I guess I will just have to let the battery run out.

[@scottcollins7513]

Funny (and sad). It seems like a calculator of that price point and power should be able to out-perform the lowly (?) CASIO fx-991EX. I did finally get the Prime to work and it is FAST (1 second or less) -- but, somewhat buggy in terms of input/parsing -- I would not have figured it out without @C Ret's comment below. I plan to make a short video at some point showing the Prime solving it.

[@GeoCalifornian]

3:10 Scotty, why didn’t you simply key in the “x” variable to the upper bound that you just solved for? /GeoCalifornian

[@scottcollins7513]

GeoCal, that never occurred to me! Good thinking. It's a little strange using x both as a constant (for the upper bound of the integration) and as a variable in the expression, but if it works, it works. Thanks for the tip.

[@ricklynch]

My HP 48sx did it. My Ti-36X Pro did it. My fx-991 ES Plus C did not do it. My fx-991EX did it. My fx-9750giii did it. My CG-50 did it. HP Prime G2 did it, instantly!

[@JohnUsp]

Very useful, thanks.

[@jeffreyfleek8655]

Can the dm42 do it?

[@scottcollins7513]

GOOD question. I had the same thought. At this point "I do not know." is the answer. I may look into this at some point -- I'm confident that a program could be written to iteratively solve it, but that would be a pain. I am curious if there is a clever way to take advantage of the built in iterative solver to solve this sort of equation.

[@jeffreyfleek8655]

@@scottcollins7513 I just recently received my DM42, so needless to say I am a newbie still learning it. But on the solver I am wondering if a program is always needed or if it can be used with some ov the calculators built in functions.

[@scottcollins7513]

@@jeffreyfleek8655 The thing that has me skeptical about getting DM42 to do it without a custom program is the fact that I doubt we can "nest" the definite integral "solver" within the numeric solver itself. I'm not optimistic. I am also, admittedly, not a power-user of the DM42 -- it is my favorite daily driver, and I have created some custom programs for it, but nothing too complicated. Perhaps some DM42 power-user might chime in on your original question...

[@jda6998]

My hp50 solves it after 2 minutes!

[@scottcollins7513]

Slower than I would have expected, but still beats the TI-36X Pro by a good margin. Thanks for the info.