4. Find an equation of the tangent plane and find a set of symmetric equations for the normal 1 line to the surface z = aIctani at the point (111%). s: 5. Find the linear approximation of x, 3;} = e\"; \"'5' centered at [011]]. E. (a) f [3:13;] 2 .172 + ya. Compare dz and $35 when :3: changes from 2 to 2.1 and 3; changes from 1 to LII). 3:: y [b] Let Hm) = sew? [M] ii \"3\"\" Show that mi] 0} and f (n 0} both ex [L [as] = {0,0} istsr but that f is not differentiable at {j}