1. The problem statement, all variables and given/known data Show that f(x) = arcsin(x) + arccos(x) = constant, for [tex] -1 \leq x \leq 1[/tex] 2. Relevant equations Some theorem involving continuity or inverse functions 3. The attempt at a solution The theorem is easy for the interval with strict bounds (differentiability on open interval and we get f'(x) = 0, so f constant on that interval), but how do I show this for the end points? The hint is to "show and use continuity" but I'm pretty sure I need to use a theorem about inverse functions. I'm just not sure how to deal with the end points -1 and 1. Any help is appreciated.