Defining Differentiation Function

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Summary:

Defining an easier way for numerical derivative at a point

Defining Differentiation Function

Zirek 02 Nov 2010 07:36

Hey Everyone,

I am new to TI-BASIC programming, as I just received my TI NSpire. I attempted to Define a variable to make an easier of way of finding the 'numerical derivative at a point'. The current way is Menu- Calculus- numerical derivative at a point - then you get a window - then you get a template. I attempted to make a way for doing this quickly, however it did not work. Can someone please find the flaws in my following program:

Define d(a,y)= d/dx (a)|x=y.

However, when I attempt to apply this by doing d(x^2,4) the calculator says: "Error Variable is not Defined".

Sorry if this is a stupid question, but can you please help :)

Re: Defining Differentiation Function

jnesselr 04 Nov 2010 00:38

I do believe the y is your problem. Remove the "=y" and try that.

Re: Defining Differentiation Function

Timothy Foster 04 Nov 2010 02:04

The Nspire seems to mimic the 68k series a lot. See if the following page helps any:

• d()

Note that I do not believe that particular command will work on an Nspire without CAS. I believe that the command you are most looking for is nDeriv(), which calculates the numerical derivative at a point. See if the Nspire has a command like that.

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Timothy Foster - @tfAuroratide
Auroratide.com - Go here if you're nerdy like me

Last edited on 04 Nov 2010 02:04 by Timothy Foster Show more