Section 14.6: Directional Derivatives & Gradient Vector
Completion requirements
Exercise 3
A table of values for the wind-chill index \(W = f(T, v)\) is given in Exercise 14.3.3 on page 923. Use the table to estimate the value of \(D_u f(-20, 30)\), where \(u = (i + j)/\sqrt{2}\).