Write a MATLAB code that can be used to calculate the hot fluid exit temperature from a heat exchanger given the hot fluid inlet temperature and the cold fluid inlet and exit temperatures. Include mass flow rates and specific heat capacities as inpu variables. Implement this for both flow conditions $($like counter$-$flow or parallel flow$)$ and calculate the required surface area for each case. Choose your own numbers and run two cases to illustrate the difference between the two flow configurations on the required surface area.