I was having an issue with transferring a data value from the [Graph] app of intersecting curves to the [Home] app on the TI-89 Titanium.
Previously on my TI-83 Plus would accomplish this task seamlessly.
[2nd] [Calc]  [First Curve] [Second Curve] [Guess]
[2nd] [Quit] [2nd] [ANS]
Currently on my TI-89 Titanium:
[F5][First Curve][Second Curve][Lower Bound][Upper Bound]
Here is where I am lost. Doing [Home] [2nd] [ANS] yields "Error: invalid ans()"
I would like to get ANY point off a graph and compute it to an exact fraction if possible.
In this case, I know that the intersection (Approx -1.0472) is exactly (-pi/3) and would like to easily see this.
So if I get the output 55.7633, I would hope to actually get 71pi/4 and not the decimal approximation. I don't want to receive the approx while not realizing there is an exact form for it.
Additionally, using exact(-1.0472) does not yield the pi fraction (I realize that the number is irrational and I used an approx, so that's why it gives me a huge decimal)
So how would I go about
1- Getting data to transfer from graph to home.
2- Getting exact pi fractions from the approximations my calculator gives me.
Thank you for reading this overly long question on a basic problem.