Work out the circumference of this circle 7.5

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?

What is the 17th term in the arithmetic sequence in which a6 is 101 and a9 is 83

Graph the system of equations. {6x−4y=−244x−8y=−32 use the line tool to graph the lines.