An airport can be cleared of fog by heating the air. The amount of
heat required depends on the air temperature and the wetness of the
fog. The figure below shows the heat [math]

**(a)**
Estimate [math]

[math]

*(Be sure you can interpret this
partial derivative in practical terms.)*

**(b)**
Make a table of values for [math]

[math]

[math]

[math]

[math]

**(c)**
Repeat **(b)** to find [math]

[math]

[math]

[math]

[math]

*(Be sure you can interpret this
partial derivative in practical terms.)*