Haha...I have been using this calculator for years and just now learned that zoom 6 resets the window settings back to standard instead of having to input them manually :)
This is the second video on using a ti-84 I have watched, just to graph a simple system of 2 linear equations. I cannot get the two linear equations to graph, though I can enter them. I hit "graph" and only the first one shows up. I followed the guys instructions to the letter, as on the last video. He is leaving things out. Yet others here seem to know what to do. Impossible, because the way to graph two equations to overlay on each other is NOT explained here.