. Prove by induction that = 1 ng 3. Remark. The sum is in fact equal to {n?(n + 1)%, but do not use this here. . Let Q(+/2) denote the set of all real numbers of the form a + bv/2, where a,b Q. (a) Show that Q(v/2) is closed under multiplication. (b) Show that every nonzero element of Q(+/2) has a multiplicative inverse in Q(v/2). Remark. This is essentially enough to prove that Q(\\/) is an ordered field, as the remaining properties are either trivial to check or inherited from R. . Let f and g be real-valued functions with the property that |f(z) g(z)|