Please help write an equation that represents the line

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?

Abank gives 6.5% interest per year. what is the growth factor b in this situation?

This is different from the first one can someone me