Anyone know how to use the Limit function on a TI-89?

[GoldenBear]

Say I wanted to find the limit of...

(x^2-2x)/sin 3x or something, how do I do it?

The little guide at the bottom says to enter:

EXPR, VAR, POINT [,DIRECTION]

So I've tried something like

limit((x^2-2x)/sin, x, 0, ->) - with -> being the arrow thign found in the catalog, but this doesn't work..

edit: What the heck? > ) makes a smiley, although the > still appears.

 

[Urinal Mint]

On my TI-85 it works like this:

limit(func,var,point)

 

[tasslex]

for direction they PROBABLY mean (-) or (+)

 

[martinm]

i thought the limit function was lim(), but i dont have it in front of me...so use whatevers in the calc's catalogue. your final code will look like this:

limit((x^2-2x)/sin(3x),x,0,-1)

the way direction works is to pick another point. thus, to approach 0 from the right, you pick any point to the right of 0 (ie, -1) and it goes from the dir point to the point youre finding the limit at. hope this helps!

p.s its been a while and im saying this from emory, but im pretty sure thats right. if not, its close, something like -1 or 0 being from the right, and 1 being from the left). good luck!

 

[VRoOMdesigns]

What the hell is a TI-89?

I'm still using my TI-83. Am I obsolete? What's going on?

 

[GoldenBear]

Ooh that works beautifully martinm. Much thanks.

 

[Mday]

the ti89 has been around for a while. it's great, but i can't afford one =(

 

[Mday]

-2/3

 

[martinm]

TI-83's ancient. The 89 is the mother of all calculators while still being SAT legal. Itt does virtually every mathematical function you would want. It has 3D graphing capability with a psuedo-realtime rotation, and best of all, symbolic manipulation. thus, you can tell it to take the derivativ of sin(x) and itll spit out cos(x), etc. It has a nice, powerful version of TI-basic, as well, and the capability to be upgraded via flash memory

 

[martinm]

Glad to have helped, GoldenBear. Email me if you ahve any other ti-89 questions, cuz i know just bout every function on that calculator. Later

 

[Belegost]

Ahh Martin beat me to it. Anyhow, good choice in calculator GB. The only complaint I have about it, is the difficulty of performing matrix operations, the TI-83s have a much simpler, quicker method that I prefer.