# Thread: How do I make a TI-89 macro?

1. ## How do I make a TI-89 macro to limit domain of functions?

Hi,

I'm wanting to set up a macro for my calculator that lets me define domain for values of X when I solve a problem.

Instead of having to type |x>=0 and x<=whatever, I want to have it hotkeyed to just drop that in whenever I hit a combination of buttons.

How do I do this?

EDIT: I'd also like to be able to set domain of my trigonometric functions, but don't know the syntax for that.

2. *Bump*

when I want to say sin^-1(1/2) when theta is > pi/6 ( or 30 degrees ), you'd think I'd enter

sin^-1(1/2)|(theta)>pi/6 , but this does not work.

Why?

3. For all functions operating on a variable, the variable must be specified on both the left and right sides of the "|" symbol. (It's also a useful practice to use a letter like "x" rather than theta - since you only need press one key to enter it.) With that in mind, try entering this...

sin-1(x) | x > 30

(Assuming approximate mode and degrees for angles.)

4. I'm in exact mode, I can't quite get it to give me the result I want with that.

I got it to work by using the solve function.

solve(sin(x)=1/2,x)|x>30 and x<360

5. Great! (It's a wonderful tool, isn't it! )

6. It's an awesome tool! Very powerful, especially in lower classes. I make sure I actually know how to do something by hand ( as it is presented to me in my math book ) before I use it.

I actually started in beginning algebra with it, and purposefully didn't learn any of the functions that worked with X until late intermediate algebra / college algebra ( Though I ended up missing the last 5 weeks of my intermediate algebra class due to some really scary health issues, so it was a lifesaver )