Use Mathematical Induction to prove that for all n ≥ 1, 1 + 1 3 + 1 32 + 1 33 +··· + 1 32n = 3 21−(1 3 2. Let f(x) = x3+9x x2−3x−4 ,then (a) find the domain of f and its zero(s). (b) find the intercept(s)of f if exists. (c) find the asymptote(s) of f if exists. (d) sketch the graph of f.