Chanis: I'm having trouble typing in tan^-1 on this calculator. I have no idea what button to press in order to switch it from regular tan to that.
It will probably be very obvious to you when I explain that inverse tan and arctan are the same thing. arctan is abbreviated to atan
so you just hit the second function like you do on most calculators
OR
you can press tan and hold it a little longer than usual and it will change to atan.
+118723 
