I am a classroom teacher and use my iPhone as the personal hotspot to connect my ipad2 to my Epson projector so I can mirror wirelessly. They both have to be on the same internet connection to do this. Can't I just use my iPad 2 as a personal hotspot, since it has AT&T 3G access.
Unfortunately, no. When the iPads got the 3G ability, one of the things they did NOT get was tethering capability. It's not built into the plans offered by the carriers. It's 3G just for the iPad - no broadcasting.
You could, however, jail break your iPad and then look into various tethering tweaks available. They work for a lot of people in making their iPads the WiFi/hotspot. But, again, that's only the jail broke iPad that can do this.
But, with stock iPads, it's a no go - you'll have to continue to use your phone. Sorry.