Hyperbolic and Inverse Trigonometric Functions How extensive is the use of hyperbolic and inverse trigonometric functions in upper-level calculus and mathematics? I've taken 3 semesters of calculus, and not one of my teachers has gone over hyperbolic functions, and barely touched on inverse trig functions (no calculus involved). I've never encountered any problems dealing with hyperbolic or inverse trig functions in any of the tests or quizzes I've received (including the AP test for AP Calculus AB). I've seen chapters devoted to these subjects in my books, but have never covered the material or been tested on the material in class (and thus never studied them). I'm wondering if these are truly arcane subjects that my teachers decided to sweep under the rug due to time constraints, or are truly important in more advanced classes. Thank you.