The temperature at the point (x, y) on a metal plate is given by the function
f(x, y) = x³+ 4xy + y² where f is in degrees Fahrenheit and x and y are in inches, with the origin at one corner of the plate. A bug is sitting at the point (2, 3) on the metal plate. Compute the (chilly) temperature at the point under the bug. Find a vector giving the direction that the bug should start to move in order to increase the temperature most rapidly. What is the rate of increase of the temperature (in degrees per inch) in this direction.