Someone please help me

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?

Suppose a least-squares regression line is given by modifyingabove y with caret equals 4.302 x minus 3.293. what is the mean value of the response variable if xequals20?

Angela rode his bike around a bike trail that was 1/4 of a mile long he rode his bike around the trail 8 * angelo says he wrote a total of 8/4 miles to russell says he's wrong and he actually and says that he actually wrote to my who is corrupt use words and trying to explain how you know.