John read 10 books in 12 months. What was his rate of reading in months per book?

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

An equation where variables are used to represent known values—function notation true or false