A wire 12 inches long is cut into two pieces. One piece is bent into a square and the other piece an equilateral triangle. Use exact values to answer the following questions. Let x be the side length of the square.
a) Express the total area A enclosed by both shapes as a function of x.
b) Find the domain of A.

Aheat pump using refrigerant-134a heats a house by using underground water at 8°c as the heat source. the house is losing heat at a rate of 60,000 kj/h. the refrigerant enters the compressor at 280 kpa and 0°c, and it leaves at 1 mpa and 60°c. the refrigerant exits the condenser at 30°c. determine: (a) the power input to the heat pump, (b) the rate of heat absorption from the water, and (c) the increase in electric power input if an electric resistance heater is used instead of a heat pump