a. Show that is harmonic. (x - 5)2 + (y - n)2+ (z -()2 b. Show the derivation for ds? = dr2 + rado2 +resin29 dxa. Show that is harmonic. (x - 5)2 + (y - n)2+ (z -()2 b. Show the derivation for ds? = dr2 + rado2 +resin29 dx