I can not find the arc key or the INV key

SOURCE: Sharp EL531WH Calculator

We are accustomed to see that the inverse of "x" to be designated as a "1/x". If using Sharp EL 531WH the inverse function you will get when you press the yellow key "2ndF" and thereafter the "X^2" key. Good luck.

SOURCE: Can you Factor on a TI-84? IF not, does the TI-89?

Well, to answer part of your question, yes... the TI-89 does factor like this. it is inputted like this:

factor(6*x^2+11*x+4,x)

Check the catalog in the TI-84 (which is 2nd-zero) and look under F for factor()

SOURCE: comma key on TI-84 Plus Siver Edition calculator.

The comma key on the TI 84 SE is above the 7 key, and it is just left of (, right of x squared, and below SIN. thats where the "," key is. If you're asking something else, please clearify. My understanding is that you don't know where the comma key is. 

SOURCE: My TI 84 will not turn on. All batteries have been

try adjusting the contrast up using 2nd + up
just keep pressing it and it should turn back

SOURCE: everytime i try to graph i get an error saying inv...

You're probably trying to graph a function that does not involve stat plot features. You can correct this by turning off the stat plot features. Press "2ND" "STAT PLOT" and then select 4:PlotsOff.