As you move to the on the number line the values of the numbers

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?

Write the expression in simplified radical form. show all steps and work including any foil method work. (hint: use the conjugate. no decimal answers.) (9-2√3)/(12+√3)

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?