Hey guys, entering 10th next year, looking for a calculator that’d last me all the way thru high school and mabye even college. 
I’m looking at a lot of TI models, like the TI-84+ and the coveted TI-89 Titanium, and I was wondering which model to buy. Amazon has these two on sale. The question is will I use these features? I’ll be in AP Calculus / AP Physics in senior year.
Can anyone help me out? (And preferrable show some form of reputable proof that TI is the best brand out there, my dad doesn’t believe it. He’s a casio lover. grr!)
I need mucho help convincing my dad.
