2_ b. A surface :(x, y) is dened implicitly by the relation x2 y _ :y :92. i. Find g and E. 8x 3y (2 marks) ii. From the previous part, write down the differential dz in terms of x, y and :. (I mark) iii. Find the equation of the tangent plane to the surface at the point (6, 3, 12) (2 marks)