In Example 2 we considered the function W = f (T, v), where W is the wind-chill index, T is the actual temperature, and v is the wind speed. A numerical representation is given in Table 1 on page 889.
(a) What is the value of f (215, 40)? What is its meaning?
(b) Describe in words the meaning of the question “For what value of v is f (220, v) = 230?” Then answer the question. 

(c) Describe in words the meaning of the question “For what value of T is f (T, 20) = 249?” Then answer the question. 

(d) What is the meaning of the function W = f (-5, v)? Describe the behavior of this function.
(e) What is the meaning of the function W = f (T, 50)? Describe the behavior of this function.