# Calculators Messed up my TI-89 somehow, don't want to reset, any suggests for {}?

1. Nov 3, 2004

### amb123

Messed up my TI-89 somehow, don't want to reset, any suggests for {}??

I don't know what I did, but now anytime my answer is going to be long, I get {} as an answer, nothing in between. Any thoughts?

:(
Angela.

2. Nov 3, 2004

### amb123

Ok, it's only with variables other than x, like w.

3. Nov 3, 2004

### amb123

Ok, sorry guys, I have found the problem. Someone loaded programs into my calculator and w now stands for wronskian, i'll need to use another variable.

thx.
Angela.

4. Dec 7, 2004

### Sterj

Can someone tell me why differential equations are needed?
I can calculate with integrals. There I know that I can calculate the Area.

F=m*a in F=d(m*v)/d(t) or something like that.
where's the different if I write F=m*a or F=d(m*v)/d(t)
Can somebody explan me that (and explain me, why m*a=d(m*v)/d(t))
(I know that a=s/t^2 and with that a=v/t)
Sorry for all these questions. arghh

5. Dec 7, 2004

### ReyChiquito

because in general $x, v, a, m,...$ are not constants, they are time dependend (amongs other things).