a) Find the linear approximation of g(x, y,z) = ( 322 + zz)e"' at x0 = (0,1,2) and use it at approximate the function at the point (0.2, 0.8, 2.1) . b) Find the linear approximation of f(x, y,z) = (1 xycos y, ~le + y2 + Z2) at x0 = (1, 1, 1) and use it at approximate f(1.02, 0.97, 1)