It sounds like the TI-89 vastly improved your ability to do calculus, to the point where it would be a shock to give up that improvement in ability. I would als

It sounds like the TI-89 vastly improved your ability to do calculus, to the point where it would be a shock to give up that improvement in ability. I would also say sine tables vastly improved people's ability to do trigonometry, back in the day... People will often express concern about growing dependent upon these devices, but I am in just the same way dependent upon pen and paper, dependent upon dictionaries, dependent upon Google, and a million other things. In a world where access to automated computation is so ubiquitous, what is the harm in, well, growing comfortable using it?