difference between TI-Nspire and TI-Nspire CAS

[Don Shepherd]

The CAS version of this calc does these additional things:

• solves systems of equations
  
• does derivatives and integrals
  
• more complex number functions
  
• expands expressions
  
• solves expressions, returns all roots
  
• factors expressions and large integers
  
• finds the max and min for a function over a specified interval
  
• find zeroes for a function
  

It may do more. This is from a cursory comparison of the reference guides for the two products.

[Namir]

Don,

Thanks for the list. You gave me several good reasons to only buy the CAS version.

Namir

[Don Shepherd]

You're welcome, Namir.

If you don't care about TI-84+ compatibility, there is no reason to buy the nSpire non-CAS.

[Namir]

Don,

I thought the non-CAS TI-nspire did not do symbolic amth, but did solve systems of linear equations, find zeros of functions, and find minima/maxima of functions. I feel it's quite the scaled down version. Sure it has the cool interface but ...

I found out today that the tables have spreadsheet-like features where you can calculate the value of a cell using values from other cells. And then, you can copy and paste that equation onto cells below. the TI-nspire will adjust cell references ... in a manner similar to Excel.

I have also realized that it's worth it to read through the manual and learn details about operating the calculator.

Namir

Edited: 4 Aug 2007, 2:54 p.m.

[Don Shepherd]

Namir, the non-CAS version does not solve systems of equations like the CAS version does. The non-CAS version does have the RREF function, so I guess that could be used to solve a system of equations if you translate the coefficients to the matrix. But the CAS version has specific templates for solving systems of equations. I have not used them (don't have the CAS version yet), but I would imagine you just type your equations in as-is and tell it to find the values of your variables.

To find zeroes of a function, or maxima or minima, on the non-CAS version I think you have to graph the equation on the geometry screen and then observe where the function crosses the x-axis (for zeroes), and for maxima and minima you do a Trace near that point on the graph and when you hit the maximum point on the curve a M is displayed next to the graph, and when you hit the minimum point a lower-case m is displayed (there are no CALC...MAX...MIN functions like on the TI-83 series, unfortunately). On the CAS version, there are specific functions for fmin, fmax, and zeroes, and I imagine you don't even need the graph for those, you just type in the equation and specify an interval and it gives you the answer.

You are right, the spreadsheet function is nicely integrated into the rest of the system, even to the point that it will populate a column with values while you drag part of a graph, then use the generated values in the column for a separate scatter-plot. Very nicely done.

I'm going to get the CAS version when it is available. At the conference I went to last month they estimated October availability for the CAS version, although it seems some companies are offering it now.

[Don Shepherd]

Namir, you don't do the Trace function (on the non-CAS version) to find zeroes, minima, and maxima. You create a point on the curve (point on function), drag it along the curve and when it gets to the maximum, minimum, or zero point, a M, m, or Z appears (correspondingly). Kind of funky, but it works. Personally, I'll use the real functions of the CAS version instead of monkeying around dragging points on a graph.

[Namir]

Don,

Thanks for the clarification of the non-CAS version. I like to have functions that work on teh CAS. I did play with the fmin and nSolve functions.

Try this link to order a TI-nspire (both versions and their software).

Namir

Edited: 5 Aug 2007, 12:45 a.m.

[Don Shepherd]

Thanks Namir. I see the cost is $217 for the CAS handheld and the Windows software, and $137 for just the handheld. At the conference I attended, sponsored by TI, each attendee got a non-CAS handheld and Windows software, free. I would definitely want the Windows software because it is much easier to develop *apps* for these calcs using the PC and mouse, and download to the unit.

I wrote the regional TI rep about getting the CAS version from TI, as a teacher. We'll see.