7. It is often suggested that K, should be changed so that (Ks) = (Ks). For example, if cos 2 Ks = cos (0-2) cos (0 + 2T) sin 0 sin (0-2) sin (0+2) 3 T then (K) = (K)-1. Show that this is true. Also, show that in this case as f + f + f = f, + f/s + fs