(a) For non negetive a,b,c,r prove that
ar(a−b)(a−c)+br(b−a)(b−c)+cr(c−a)(c−b)≥0
(b) Find an inequality for non negative a,b,c with a4+b4+c4+abc(a+b+c) on the greater side.
(c) Prove that if abc=1 for non negative a,b,c, a4+b4+c4+a3+b3+c3+a+b+c≥ca2+b2+ab2+c2+bc2+a2+3