Hi,

I hope someone can help. How does my calculator know what the range restrictions are on a inverse trig function? I know that inverse trig functions have a one-to-many mapping, so you must restrict the range. For example, I know that for arccosin it is convention to restrict the range between 0 and pi. I know that you could very well make the range for arccos between pi and 2pi. So why does my calculator choose the solution that has the range between 0 and pi? I input arccos(√2/2) on my calculator and I get pi/4. Why doesn't my calculator choose the solution 7pi/4? Both solutions are just as correct, from my understanding, but all I want to know is WHY my calculator chooses the first solution over the second one. I hope this makes sense.

Sincerely,

Olivia