Problem : What is arccos()?

+2, +2, where n is an integer.

Problem : What is arcsin(0)

, where n is an integer.

Problem : What is arccos()?

There is no solution, because there exists no angle whose cosine > 1.

Problem : Why aren't the inverse relations functions?

The inverse relations aren't functions because they don't assign a specific output to each input.

Problem : What are the domains of arcsine, arccosine, and arctangent?

The domains of arcsine and arccosine are [- 1, 1]. The domain of arctangent is all real numbers. Note: Although they aren't functions, the term domain can be used to describe the possible inputs of the relations.