What two different combinations of radius and height produce two cylinders with nearly the same volume ?

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?

The amount of energy it takes to lift a box might be a function of which of the following

Christina can paint 420 square feet in 105 minutes. which unit rate describes the scenario?