G N !N, g(x) = x2 (b) f Q !Q, f (x) = 3x2 4;G R !R, g(x) = x2 SOLUCION´ (a) g f (x) = (x1)2;I j h k v Z h j Z s Z l v k y i h Z ^ j _ k m Publications du BIT, Bureau international du Travail, CH1211 G _nève m Saidur Rahman 2¢'ÑZ'î bg fbg