2. (2pts) Let f(x, y) = x cos(4y), x= uv , and y=u'tv . Find of Your answer may contain x, y, u, and/or v.\\_"'_I '" "" _"""_" _' "" In" K\" "3 ' 5. (Zpts) Suppose the xy-plane is transposed over a heated metal plate. The temperature (in Fahrenheit) of the metal plate at the point (x. y) is given by the function: Tut, y} = Jr\"I +oos'1(y) +80 . Suppose you are standing on the metal plate in your bare feet at the point [3,?) . In the direction of which unit vector should you move to cool your feet as quickly as possible {be exact)? 6. (2pts) Find an equation of the tangent plane to the surface given by A)? + yz + 21 = 5 at the point (1,2,1) on the surface