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TI 89 variable problem?

ZombieLeeZombieLee Registered User regular
edited February 2012 in Help / Advice Forum
I've got this strange problem that just sprung up on my TI-89 where entering xy makes the calculator recognize one variable "xy" as opposed to two variables multipled "x*y", so for example if I try to differentiate xy wrt x it will come up with answer 0 as opposed to y. Has this happened to anyone else?

ZombieLee on


  • SpoitSpoit *twitch twitch* Registered User regular
    I'm pretty sure that's the intended behavior, for if you want to actually have named variables and the like

  • UncleSporkyUncleSporky Registered User regular
    edited February 2012
    I think Spoit is right. You could type Poop * Butt if you wanted, but not PoopButt, because then you're referring to an entirely new variable.

    UncleSporky on
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  • XaviarXaviar Registered User regular
    As a bit of a TI-89 enthusiast, I can confirm, this is working as intended. The 89 and 92 have a much more sophisticated variable / programming aspect than the previous calculators. This is awesome for some people (like me). Some people just get endlessly frustrated with it. I don't know what you're actually using it for, but if you find it is causing you more headaches than solving problems, and you don't need the features you would otherwise be missing, the 83+ is a great graphing calculator without all the bells and whistles.

  • SpoitSpoit *twitch twitch* Registered User regular
    Which is why I use RPN on the HP 49 instead /nothelpful :P

  • BlazeFireBlazeFire Registered User regular
    Uhm, how does RPN help that? If you type X, Y, [enter] you'll still get XY on one line.

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