In Response To 'Re: Trigonometry input question'
What is simple and easy and familiar with one calculator can be complicated and unfamiliar with another and especially with some piece of software.
Mathematica can almost certainly do a vast list of things your calculator cannot, but allowing you to enter and solve problems in almost exactly the same way as your calculator is almost certainly not something it will ever do.
I would suggest sticking with your calculator until you get to a point where it simply cannot solve some problem for you and then choose the least worst alternative. I can't help with that decision. But you might check to see if someone has written a clone of your calculator in software to run on your computer and whether that is bug free and dependable and might work for you.