1, Convergent sequence: show that lim, ... (225-) = 3 where n N. 2, Sketch the following two subsets of R2, comment if they are closed or open sets. (@) S = {(z,y) R?|z? + 2y% = 4} (b) T = {(z,y) R?|z? + 3 (a) Find the values of f(1,2), f(a,a), and f(a + h,b) f(a,b) (b) Show that f(2z,2y) = 2 f(z,y) and that f(tz, ty) = t*f(z,y) for all . 4, Let f(z,y) = 3z 2zy + >. Find the expression of p = [f(z + h,y) f(z,y)]/h and show that of h0 ox 5, Find the first-order partial derivatives % and % for each of the following functions: (@) z = z2 + 3% (b) z = (z +9)* ()z="/y (d) P ml;"zylf