1. Consider the space of absolutely convergent sequences equipped with the following norm 1/2 1I (21, ..., In, ...) 1/1,2= Cla;1+( 12,12 (0.1) j=1 j=1 a). Prove that || . |/1,2 is a norm. b). Is this norm equivalent to the standard || ~ |1= E lx;? 1/2 c). Is it equivalent to || ~ ||2=