# Opinions on graphing calculators?

Discussion in 'General Electronics Chat' started by taco3rd, Dec 9, 2013.

1. ### taco3rd Thread Starter New Member

Oct 22, 2013
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I'm a mechanical engineering student. I'm looking for thoughts on a good graphing calculator, that will be sufficient going forward. Up until now I've been using the online utility bcalc.net. That was sufficient for my online algebra classes, but I'm moving into on-campus calculus courses starting this January.

I've been researching the TI-84 Plus C Silver Edition, but I have no clue if that would be a wise choice, or not. My course syllabus mentions that the TI-89, TI-92 and equivalents are not allowed. I'm not sure why.

Any thoughts would be appreciated. Thanks!

2. ### tshuck Well-Known Member

Oct 18, 2012
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It's because the TI-89 can do what you are supposed to be learning automatically. The TI-84 it's largely sufficient for what you will be doing in your calculus classes, but the TI-89 would be quite useful in your engineering courses...

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3. ### mcgyvr AAC Fanatic!

Oct 15, 2009
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Don't they have graphing calculator apps now for android/iphones?.. Not sure a graphing calculator is needed anymore.. well assuming you have a smartphone..

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4. ### tshuck Well-Known Member

Oct 18, 2012
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If they won't let you use a graphing calculator that does it all, they certainly aren't going to let you text your buddies regarding the answer.

5. ### taco3rd Thread Starter New Member

Oct 22, 2013
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I have no doubt that they do, mcgyvr, but I'm not sure how easy it would be to use, with all the buttons and options there are on a calculator. I have a hard enough time with text messages.

6. ### shteii01 AAC Fanatic!

Feb 19, 2010
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Contact the instructor and find out why. You may buy some other calculator (I am Casio fan myself) and find out that it has the same features that disqualified the other two calculators.

Also. This sort of thing does happen in some higher level courses. In my Controls class (third year college course) the instructor required us to use basic scientific calculator, no graphing calculators at all. I had to go buy one since all I had are my old graphing calculators, TI-81 and Casio CFX-9850G.

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7. ### MrSoftware Active Member

Oct 29, 2013
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The TI-85 got me through just fine (many, many years ago...), is that one allowed?

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8. ### taco3rd Thread Starter New Member

Oct 22, 2013
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I believe that would be ok. I don't think they make that particular model anymore. It seems the go-to calculators from TI are the 84, 89 and the new Nspire models.

9. ### bug13 Well-Known Member

Feb 13, 2012
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I have 3 different calculators, just pick them up on e-bay, second hand one are cheap!

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10. ### taco3rd Thread Starter New Member

Oct 22, 2013
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I decided to go with a TI Nspire CX CAS. Thanks for the input.

11. ### crutschow Expert

Mar 14, 2008
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I've never quite figured this out -- what do you do with the crude little graph that the calculator generates?

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12. ### #12 Expert

Nov 30, 2010
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I too am baffled. In first semester calculus I was required to describe the graph of the function verbally, with crossing points of the x and y axis. Now, people want a machine to do what we used to do in our head. The generation before me probably laughs at me for using a "scientific" calculator instead of a slide rule.

13. ### crutschow Expert

Mar 14, 2008
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Well I used a slide rule for a number of years before the first pocket scientific calculator (the famous HP-35) and I thought it was the greatest improvement ever in making my engineering work a lot easier (aside form the personal computer which can later). And no more misplaced decimal points. Anybody whose ever used a slide rule would not look down on someone who uses a scientific calculator. You only used a slide rule because there was nothing better available.

14. ### taco3rd Thread Starter New Member

Oct 22, 2013
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You still have to do the math in your head with pen and paper. I think the calculator, at this point, is just used to verify your work, and get used to using the calculator.

15. ### #12 Expert

Nov 30, 2010
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What I think you're saying is, if you don't already know how to do the math, the calculator is useless. That is why calculators are allowed in most classes. They are dead accurate and a lot faster than looking up trig functions and logarithms. Because the point of most classes to to get you to understand how to get the answer, the calculator is merely convenient. It won't find the answer, it just does the math.

16. ### crutschow Expert

Mar 14, 2008
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I would say that the person is doing the math, the calculator is just doing the grunt-work calculations. For fun, try doing the cube root of an arbitrary number by hand, something a calculator can do in milliseconds.

17. ### dean_1230 New Member

Apr 17, 2013
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ok, challenge accepted! Given the arbitrary number 27, the cube root is 3...

that was easy!

Seriously, I got through my undergraduate classes and 20+ years as an engineer with an HP-15C! Gawd, I still love the way that brick fits in my hand! If I need to graph something simple, I use Excel. If it's more complex, I use R.

18. ### crutschow Expert

Mar 14, 2008
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I started with an HP-25, then to an HP-29, then to an HP-15C, with my final being an HP-42. The 42 had some interesting advanced capability like being able to directly perform complex number calculations in the form x + iy (for example it would give the proper answer for the $\sqrt{-1}$ as i ). You could also put in a mathematical formula of several variables and it would iteratively solve for one of the (unknown) variable values if you input values for the other variables. That would work even for transcendental equations which were difficult to be solved explicitly for the unknown [such as solving for x where y = sin(x)/x].

19. ### tcmtech Well-Known Member

Nov 4, 2013
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Back around 2000 I went back to school in my late 20's as a OTA student for electrical engineering.
(As someone with some years of real hands on life experience it was a total waste of time money and brain cells.)

Anyway the TI 83 silver was my first choice of calculators to use. Once I wore it out I went up to a TI Voyage! Still use it all the time now too!

Best part with the big graphing calculators is they have enough subprograms and functions in them that hiding notes and info for other non math heavy classes and tests is easy!

I used to write basic math programs for some of my classes to make things easier then for stuff like my chem and physics classes I would hide loads of notes and cheats in the coding for the math programs! If anyone ran the programs they worked like normal but if you went in and read the actual code there would be countless lines of nothing but notes hid between the actual programs working lines of code.