The hot gas lines need to be insulated? a never b always c if they are exposed to cold temperatures that could cause the refrigerant to condense in the line d for systems using hfc refrigerants

  the correct answer is : binding price ceilings encourage the formation of a black market

Ok i’m not good at this but imma try : )

You're asking in the ap section, so i'll give the ap calculus-style answer. alternatively, you can find the vertex of the parabola and use the "y"-coordinate as the answer.

the maximum height can occur at a critical number, that is, a number  such that  .

the derivative of  can be calculated as follows:



find a value of  that is a zero of the derivative:


this is parabola that is opening downward; we can assume there is a maximum at  .

to find that maximum, calculate  .