1. The problem statement, all variables and given/known data Ok, this is not really a problem, but I need help on understanding the basics of sin, cos, tan, and their inverses. i was looking at http://www.analyzemath.com/DomainRange/domain_range_functions.html and it was saying that the domain for sin and cos is (-inf , + inf) and then for tan it is All real numbers except pi/1 + n*Pi but then for csc, it is All real numbers except n*Pi Can you explain why? I think I'm having trouble with figuring out how to find domains and I want to understand this before I start calculus. Please explain.