1. (3.) Find and classify all critical points of the function f(:l:,y) = 1:3 - y3 - 3231+ 2. (Show your work.) (b) Use Lagrange multipliers to nd the maximal and minimal value of f(:1:, y, z) = xyz +22 restricted to the surface 1'2 + y2 + 222 = 3 in R3