Can someone helppp please

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?

(urgent ) use pi 3.14 to estimate the circumference of the circle to the nearest hundredth middle is 4in (urgent )

Ann and betty together have $60 ann has $9 more than twice betty’s amount how much money dose each have